Danh sách câu hỏi:

Câu 7:

Sarah will be very annoyed if Dave _____ her this evening.

Xem đáp án

Câu 11:

When I got to 16, some of my friends left school to get a job, but most _____.

Xem đáp án

Câu 15:

Dave apologized _____ for forgetting about our appointment.

Xem đáp án

Câu 22:

Lan: "Do you think it's important for young people to keep fit?”

Nam: “____________________.”

Xem đáp án

Câu 23:

Dad: "What's the weather forecast?"

Mum: “________________.”

Xem đáp án

Câu 24:

Read the passage and mark the letter A, B, C or D to complete the passage.

Japan's Mount Fuji will become a World Heritage Site in June. The United Nations (U.N.) decided on April the 30th to give the famous mountain UNESCO World Heritage (25) _____. The U.N. team (26) _____ made the decision said Fuji was very important to Japanese religion and art. They also said that the 3,776-meter-high volcano was important outside of Japan too. Fuji-san (as Japanese people call it) has been a mountain for more than 1,000 years. Priests say that when you climb it, you move from the "everyday world" at the bottom, to the "world of gods, Buddha and death" at the top. They believe

people can (27) _____ their sins by climbing to the top and coming back down again.

(28) _____ Mount Fuji is a major tourist destination. It is very popular with hikers, who want to see the rising sun from its peak. More than 318,000 hikers visited the mountain last summer, with up to 15,000 people climbing each day. Local residents are now worried the World Heritage status will mean more visitors. That means there will be more litter and environmental problems. The local government may ask people to pay to climb the mountain to help preserve its (29) ______. Governor Shomei Yokouchi said: "It's likely we'll ask mountain climbers to help financially with keeping the mountain

clean." Another idea being talked about is to limit the daily number of hikers allowed to the top.

Điền vào đáp án 25

Xem đáp án

Câu 25:

Read the passage and mark the letter A, B, C or D to complete the passage.

Japan's Mount Fuji will become a World Heritage Site in June. The United Nations (U.N.) decided on April the 30th to give the famous mountain UNESCO World Heritage (25) _____. The U.N. team (26) _____ made the decision said Fuji was very important to Japanese religion and art. They also said that the 3,776-meter-high volcano was important outside of Japan too. Fuji-san (as Japanese people call it) has been a mountain for more than 1,000 years. Priests say that when you climb it, you move from the "everyday world" at the bottom, to the "world of gods, Buddha and death" at the top. They believe

people can (27) _____ their sins by climbing to the top and coming back down again.

(28) _____ Mount Fuji is a major tourist destination. It is very popular with hikers, who want to see the rising sun from its peak. More than 318,000 hikers visited the mountain last summer, with up to 15,000 people climbing each day. Local residents are now worried the World Heritage status will mean more visitors. That means there will be more litter and environmental problems. The local government may ask people to pay to climb the mountain to help preserve its (29) ______. Governor Shomei Yokouchi said: "It's likely we'll ask mountain climbers to help financially with keeping the mountain

clean." Another idea being talked about is to limit the daily number of hikers allowed to the top.

Điền vào đáp án 26

Xem đáp án

Câu 26:

Read the passage and mark the letter A, B, C or D to complete the passage.

Japan's Mount Fuji will become a World Heritage Site in June. The United Nations (U.N.) decided on April the 30th to give the famous mountain UNESCO World Heritage (25) _____. The U.N. team (26) _____ made the decision said Fuji was very important to Japanese religion and art. They also said that the 3,776-meter-high volcano was important outside of Japan too. Fuji-san (as Japanese people call it) has been a mountain for more than 1,000 years. Priests say that when you climb it, you move from the "everyday world" at the bottom, to the "world of gods, Buddha and death" at the top. They believe

people can (27) _____ their sins by climbing to the top and coming back down again.

(28) _____ Mount Fuji is a major tourist destination. It is very popular with hikers, who want to see the rising sun from its peak. More than 318,000 hikers visited the mountain last summer, with up to 15,000 people climbing each day. Local residents are now worried the World Heritage status will mean more visitors. That means there will be more litter and environmental problems. The local government may ask people to pay to climb the mountain to help preserve its (29) ______. Governor Shomei Yokouchi said: "It's likely we'll ask mountain climbers to help financially with keeping the mountain

clean." Another idea being talked about is to limit the daily number of hikers allowed to the top.

Điền vào đáp án 27

Xem đáp án

Câu 27:

Read the passage and mark the letter A, B, C or D to complete the passage.

Japan's Mount Fuji will become a World Heritage Site in June. The United Nations (U.N.) decided on April the 30th to give the famous mountain UNESCO World Heritage (25) _____. The U.N. team (26) _____ made the decision said Fuji was very important to Japanese religion and art. They also said that the 3,776-meter-high volcano was important outside of Japan too. Fuji-san (as Japanese people call it) has been a mountain for more than 1,000 years. Priests say that when you climb it, you move from the "everyday world" at the bottom, to the "world of gods, Buddha and death" at the top. They believe

people can (27) _____ their sins by climbing to the top and coming back down again.

(28) _____ Mount Fuji is a major tourist destination. It is very popular with hikers, who want to see the rising sun from its peak. More than 318,000 hikers visited the mountain last summer, with up to 15,000 people climbing each day. Local residents are now worried the World Heritage status will mean more visitors. That means there will be more litter and environmental problems. The local government may ask people to pay to climb the mountain to help preserve its (29) ______. Governor Shomei Yokouchi said: "It's likely we'll ask mountain climbers to help financially with keeping the mountain

clean." Another idea being talked about is to limit the daily number of hikers allowed to the top.

Điền vào đáp án 28

Xem đáp án

Câu 28:

Read the passage and mark the letter A, B, C or D to complete the passage.

Japan's Mount Fuji will become a World Heritage Site in June. The United Nations (U.N.) decided on April the 30th to give the famous mountain UNESCO World Heritage (25) _____. The U.N. team (26) _____ made the decision said Fuji was very important to Japanese religion and art. They also said that the 3,776-meter-high volcano was important outside of Japan too. Fuji-san (as Japanese people call it) has been a mountain for more than 1,000 years. Priests say that when you climb it, you move from the "everyday world" at the bottom, to the "world of gods, Buddha and death" at the top. They believe

people can (27) _____ their sins by climbing to the top and coming back down again.

(28) _____ Mount Fuji is a major tourist destination. It is very popular with hikers, who want to see the rising sun from its peak. More than 318,000 hikers visited the mountain last summer, with up to 15,000 people climbing each day. Local residents are now worried the World Heritage status will mean more visitors. That means there will be more litter and environmental problems. The local government may ask people to pay to climb the mountain to help preserve its (29) ______. Governor Shomei Yokouchi said: "It's likely we'll ask mountain climbers to help financially with keeping the mountain

clean." Another idea being talked about is to limit the daily number of hikers allowed to the top.

Điền vào đáp án 29

Xem đáp án

Câu 29:

Read the passage and mark the letter A, B, C or D to answer the questions.

People in the UK enjoy fewer years of good health before they die than the citizens of most comparable European countries as well as Australia and Canada, a major report shows. While life expectancy has improved by 4.2 years in the UK over the two decades, other countries have improved faster. In 2010, Spain topped the league. Its people could expect 70.9 years of healthy life - before disease and disability began to take a toll. Second came Italy, with 70.2 years and third was Australia, on 70.1 years. In the UK, we can expect 68.6 healthy years of life.

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers - cancer, heart disease, stroke, respiratory and liver diseases. Drinking and drug use have been the main issues behind the worsening of the UK's ranking in early deaths among adults aged 20-54. In 2010, drugs were the sixth leading cause of death in this age group and alcohol was 18th - up from 32nd and 43rd place respectively 20 years earlier.

Hunt will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year. "Despite real progress in cutting deaths, we remain a poor relative to our global cousins on many measures of health, something I want to change," he said. "For too long we have been lagging behind and I want the reformed health system to take up this challenge and turn this shocking underperformance around.” However, the problem is only in part to do with hospital care - much of it is about the way we live. Our diet, our drinking and continuing smoking habits all play a part, which assumes its responsibilities on 1 April.

 The best title for this passage could be ________.

 

 

Xem đáp án

Câu 30:

Read the passage and mark the letter A, B, C or D to answer the questions.

People in the UK enjoy fewer years of good health before they die than the citizens of most comparable European countries as well as Australia and Canada, a major report shows. While life expectancy has improved by 4.2 years in the UK over the two decades, other countries have improved faster. In 2010, Spain topped the league. Its people could expect 70.9 years of healthy life - before disease and disability began to take a toll. Second came Italy, with 70.2 years and third was Australia, on 70.1 years. In the UK, we can expect 68.6 healthy years of life.

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers - cancer, heart disease, stroke, respiratory and liver diseases. Drinking and drug use have been the main issues behind the worsening of the UK's ranking in early deaths among adults aged 20-54. In 2010, drugs were the sixth leading cause of death in this age group and alcohol was 18th - up from 32nd and 43rd place respectively 20 years earlier.

Hunt will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year. "Despite real progress in cutting deaths, we remain a poor relative to our global cousins on many measures of health, something I want to change," he said. "For too long we have been lagging behind and I want the reformed health system to take up this challenge and turn this shocking underperformance around.” However, the problem is only in part to do with hospital care - much of it is about the way we live. Our diet, our drinking and continuing smoking habits all play a part, which assumes its responsibilities on 1 April.

 The word “cardiovascular” in paragraph 2 could be best replaced by ________.

 

 

Xem đáp án

Câu 31:

Read the passage and mark the letter A, B, C or D to answer the questions.

People in the UK enjoy fewer years of good health before they die than the citizens of most comparable European countries as well as Australia and Canada, a major report shows. While life expectancy has improved by 4.2 years in the UK over the two decades, other countries have improved faster. In 2010, Spain topped the league. Its people could expect 70.9 years of healthy life - before disease and disability began to take a toll. Second came Italy, with 70.2 years and third was Australia, on 70.1 years. In the UK, we can expect 68.6 healthy years of life.

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers - cancer, heart disease, stroke, respiratory and liver diseases. Drinking and drug use have been the main issues behind the worsening of the UK's ranking in early deaths among adults aged 20-54. In 2010, drugs were the sixth leading cause of death in this age group and alcohol was 18th - up from 32nd and 43rd place respectively 20 years earlier.

Hunt will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year. "Despite real progress in cutting deaths, we remain a poor relative to our global cousins on many measures of health, something I want to change," he said. "For too long we have been lagging behind and I want the reformed health system to take up this challenge and turn this shocking underperformance around.” However, the problem is only in part to do with hospital care - much of it is about the way we live. Our diet, our drinking and continuing smoking habits all play a part, which assumes its responsibilities on 1 April.

 According to the passage, what is NOT the cause of death in the UK?

Xem đáp án

Câu 32:

Read the passage and mark the letter A, B, C or D to answer the questions.

People in the UK enjoy fewer years of good health before they die than the citizens of most comparable European countries as well as Australia and Canada, a major report shows. While life expectancy has improved by 4.2 years in the UK over the two decades, other countries have improved faster. In 2010, Spain topped the league. Its people could expect 70.9 years of healthy life - before disease and disability began to take a toll. Second came Italy, with 70.2 years and third was Australia, on 70.1 years. In the UK, we can expect 68.6 healthy years of life.

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers - cancer, heart disease, stroke, respiratory and liver diseases. Drinking and drug use have been the main issues behind the worsening of the UK's ranking in early deaths among adults aged 20-54. In 2010, drugs were the sixth leading cause of death in this age group and alcohol was 18th - up from 32nd and 43rd place respectively 20 years earlier.

Hunt will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year. "Despite real progress in cutting deaths, we remain a poor relative to our global cousins on many measures of health, something I want to change," he said. "For too long we have been lagging behind and I want the reformed health system to take up this challenge and turn this shocking underperformance around.” However, the problem is only in part to do with hospital care - much of it is about the way we live. Our diet, our drinking and continuing smoking habits all play a part, which assumes its responsibilities on 1 April.

 According to the passage, Hunt is showing his attempt to ________.

 

 

Xem đáp án

Câu 33:

Read the passage and mark the letter A, B, C or D to answer the questions.

People in the UK enjoy fewer years of good health before they die than the citizens of most comparable European countries as well as Australia and Canada, a major report shows. While life expectancy has improved by 4.2 years in the UK over the two decades, other countries have improved faster. In 2010, Spain topped the league. Its people could expect 70.9 years of healthy life - before disease and disability began to take a toll. Second came Italy, with 70.2 years and third was Australia, on 70.1 years. In the UK, we can expect 68.6 healthy years of life.

Hunt said the UK was a long way behind its global counterparts and called for action by local health commissioners to tackle the five big killers - cancer, heart disease, stroke, respiratory and liver diseases. Drinking and drug use have been the main issues behind the worsening of the UK's ranking in early deaths among adults aged 20-54. In 2010, drugs were the sixth leading cause of death in this age group and alcohol was 18th - up from 32nd and 43rd place respectively 20 years earlier.

Hunt will on Tuesday announce a strategy to tackle cardiovascular disease, which he says could save 30,000 lives a year. "Despite real progress in cutting deaths, we remain a poor relative to our global cousins on many measures of health, something I want to change," he said. "For too long we have been lagging behind and I want the reformed health system to take up this challenge and turn this shocking underperformance around.” However, the problem is only in part to do with hospital care - much of it is about the way we live. Our diet, our drinking and continuing smoking habits all play a part, which assumes its responsibilities on 1 April.

The word “it” in paragraph 2 refers to ________? 

Xem đáp án

Câu 34:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

What is the best title for the passage? 

Xem đáp án

Câu 35:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

According to the passage, an advantage of using a photoflash is that it _____. 

Xem đáp án

Câu 36:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

 The word "ignited" in paragraph 1 is closest in meaning to ______.

Xem đáp án

Câu 37:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

Which of the following is TRUE about the function of the glass in the first flashbulbs? 

Xem đáp án

Câu 38:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

The word "it" in paragraph 2 refers to _____. 

Xem đáp án

Câu 39:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

The word "momentarily"  in paragraph 2 is closet in meaning to ______. 

Xem đáp án

Câu 40:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

According to the passage, what helps a flashbulb burn longer? 

Xem đáp án

Câu 41:

Read the passage and mark the letter A, B, C or D to answer the following questions.

Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time (1ess that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion - that is, a light-sensitive coating on photographic film, paper, or glass - will, however, record much shorter bursts of light. A photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but the earliest form, first used in 1864, was a paper bag containing

magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported that "this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.”

The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum, capable of being ignited in an atmosphere of pure oxygen at low pressure, were introduced only in the 1920's. In the earliest type, the metal was separated from the oxygen by a thin glass bulb. The flash was fired by piercing the bulb and allowing the oxygen to come into contact with the metal, which ignited spontaneously. Later bulbs were fired by an electric battery, which heated the wire by passing a small current through it. Other combinations, such as the pairing of oxygen difluoride with zirconium, have also been used. In each case enough energy is given out to heat the oxidizable metal momentarily to a white hot emission of visible light. The smoke particles are so small that they cool rapidly; but since they are white, they contribute to the brilliance by reflecting the light from their still glowing neighbors. A slightly bigger form of the metal will burn for a longer time.

Which of the following most accurately reflects the main idea of the last paragraph? 

Xem đáp án

Câu 45:

"I'll buy you a new bicycle if you stop eating junk food,” said Lam’s mother.

Xem đáp án

Câu 46:

You should have made your children do housework as soon as they were able to do so.

Xem đáp án

Câu 47:

When the birth rate is high, the expectation of life is low.

Xem đáp án

Câu 49:

He donated a lot of money to environmental protection campaigns. He was admired for that.

Xem đáp án

4.6

41 Đánh giá

73%

17%

5%

5%

0%