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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.It can be inferred from the passage that_________
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.According to the author, which of the following reasons disrupt travelers’ sleep?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.On the subject of avoiding jet lag the article_________
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.Life in the UniverseExobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.Question:All of the following are mentioned in the passage as necessary for the development of life except
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.According to the article, _________
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.Life in the UniverseExobiology is the study of life that originates from outside of Earth. As yet, of course, no such life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extrateưestrial life forms might be like.What sorts of planets are most likely to develop life? Most scientists agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble Earth’s. Water is an important solvent involved in many biological processes. Biogeochemical cycles are the continuous movement and transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’s climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and bum out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problem. First of all, planets in their habitable zones will be so close to the star that they will be “tidally locked” – that is one side of the planet will always face the star in perpetual daylight with the other side in the perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem.Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the orbits must be a good distance from one another. Interestingly, the amount of space needed is roughly the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two.Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas giants, such as Saturn and Jupiter,.in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth.Question:What is the topic of the passage?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.The direction you fly in_________
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:What will Martha and Ellen probably do next time it rains?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.The word “malady” is closest in meaning to
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:What did Martha think about being outside?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.Jet lag _________
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:The word “company” in the last paragraph is closest in meaning to
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.The word “It” refers to_________
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 20 to 25.FIRST TIME IN THE AIRWhen John Mills was going to fly in an aeroplane for the first time, he was frightened. He did not like the idea of being thousands of feet up in the air. “ I also didn't like the fact that I wouldn't be in control,” says John.“I'm a terrible passenger in the car. When somebody else is driving, I tell them what to so. It drives everybody crazy.”However John couldn't avoid flying any longer. It was the only way he could visit his grandchildren in Canada. “I had made up my mind that I was going to do it, I couldn't let my son, his wife and their three children travel all the way here to visit me. It would be so expensive for them and I know Tom's business isn't doing so well at the moment – it would also be tiring for the children – it's a nine-hour flight!” he says.To get ready for the flight John did lots of reading about aeroplanes. When he booked his seat, he was told that he would be flying on a Boeing 747, which is better known as a jumbo jet. “I needed to know as much as possible before getting in that plane. I suppose it was a way of making myself feel better. The Boeing 747 is the largest passenger aircraft in the world at the moment. The first one flew on February 9th 1969 in the USA. It can carry up to 524 passengers and 3.400 pieces of luggage. The fuel for aeroplanes is kept in the wings and the 747 is wings are so big that they can carry enough fuel for an average car to be able to travel 16,000 kilometres a year for 70 years. Isn't that unbelievable? Even though I had discovered all this very interesting information about the jumbo, when I saw it for the first time, just before I was going to travel to Canada, I still couldn't believe that something so enormous was going to get up in the air and fly. I was even more impressed when I saw how big itwas inside with hundreds of people!”The biggest surprise of all for John was the flight itself. “The take-off itself was much smoother than I expected although I was still quite scared until we were in the air. In the end, I managed to relax, enjoy the food and watch one of the movies and the view from the window was spectacular. I even managed to sleep for a while! Of course,” continues John, “the best reward of all was when I arrived in Canada and saw my son and his family, particularly my beautiful grandchildren. Suddenly, I felt so silly about all the years when I couldn't even think of getting on a plane. I had let my fear of living stop me from seeing the people I love most in the world. I can visit my son and family as often as I like now!”Why did John Mills fly in an aeroplane?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions .Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a “clock” that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the circadian clock (from the Latin, circa “about” + dies “day”).This body clock programmes us to be sleepy twice a day, between 3-5 a.m and again between 3-5 p.m. Afternoon tea and siesta times are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travelers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the circadian clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to shrink our day. That is why travelling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are “extending” your day, thus travelling in the natural direction of your internal clock. Flying eastward will involve “shrinking” or reducing your day and is in direct opposition to your internal clock’s natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this: Changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal circadian clock and working longer hours. Sleep loss, jet lag and fatigue can seriously affect our ability to function well. Judgment and decision-making can be reduced by 50%, attention by 75 percent, memory by 20 percent and communication by 30 percent. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone.The main function of the body clock is to_________
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 44      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 43      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 42      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:What does Martha mean when she says “It meant that I would have to entertain myself”?
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 41      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 40      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 39      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:What was keeping Martha inside?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question:The word “grumpy” in paragraph 1 is closest in meaning to
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 38      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.Rain pounded down on the roof. I was trying to read but the sound was too loud. I couldn’t help myself from being a little grumpy. I wanted to be outside playing, but the rain was keeping me inside.My mom had gone to the grocery store, and my dad was spending Saturday at the office. I had planned to spend the day hiking, but Mother Nature decided that today was the perfect day for rain.It meant that I would have to entertain myself. I spent most of the morning playing with my stuffed animals and reading. I was sitting next to the window staring out when I got a strange idea: why not just go outside anyway?I put on my boots and a big raincoat and stepped out into the wet world. It was raining hard but it wasn’t cold. All I could hear were raindrops and the wind. I decided to go on my hike anyway.My feet didn’t make any sound on the wet ground and the forest seemed different. I went to my favourite place and sat down. In the summer, my best friend Ellen and I would come here and sit for hours. It was our special place. All of a sudden, I thought I heard someone shouting my name. I turned and saw Ellen walking up behind me.“Oh my Gosh! It’s really you, Martha!” she said. “I can’t believe that you are out here right now. I thought I would be the only person crazy enough to go for a walk in the rain.”I was very happy to have some company. We decided that hiking in the rain was just as fun as hiking in the sunshine. We planned on hiking in the rain again.Question: What is the best title for the story?
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 37      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 36      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the latter A, B, C or D on your answer sheet to indicate the word or phrase that best fits each of the numbered blanks . Fill in the appropriate word in question 35      Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a  night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age.      This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep  at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon.            By Tim Falla and Paul A.Davies, Solutions Advanced. OUP
Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.          Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.         Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.          The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.The word “intermittently” in live 4 is closest in meaning to _____
Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.          Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes. These trails incorporate no directional information and may be followed by other ants in either direction.         Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.          The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.What does the passage mainly discuss?