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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 the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.A paragraph following the passage would most probably discuss_________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.According to the passage, what group of people will probably first from the use of the microprocessor?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.The researcher mentioned in the passage are concerned about unwanted noise because it can_________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.The microprocessor described in the passage will probably be used for_________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.The passage discusses a way to deal with an offensive noise by_________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.The passage compares sound to_________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions. Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. Once way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. Using a noisemarker controlled by a microprocessor, engineers have produced sound waves that are half a wavelength out of phase with those of the noise to be quieted-each crest is matched to a trough, and vice versa. Once the researchers have recorded the offending sound, a microprocessor calculates the amplitude and wavelength of sound that will cancel out the crests and troughs of noise. It then produces an electric current that is amplified and fed to a loudspeaker, which produces anti-sound and wipes out the noise. If the anti-sound goes out of synchronization, a microphone picks up the leftover sound and sends it back to the microprocessor, which changes the phase of the anti- sound just enough to cause complete silence.The research team has concentrated on eliminating low-frequency noise from ship engines, which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.What is the main purpose 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 the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.It can be inferred from the passage that limestone deposits serve as the basis of________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.According to the passage, red algae is________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.Brown algae would most likely be found________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.Green algae is generally found________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.Algae remnants found in Africa are________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.The word "pigment" at the end of the first paragraph means________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.Which of the following is NOT true about algae?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions.Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.What is the author's main purpose?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks.When you wave to a friend, you are using sign language. When you smile at someone, you mean to be (9) ______. When you put one finger in front of your (10) ______, you mean, "Be quiet." Yet, people in different countries may use different sign languages. Once an Englishman was in Italy he could speak a little Italian. One day while he was walking in the street, he felt (11) ______ and went into a restaurant. When the waiter came, the Englishman opened his mouth, put his fingers into it and took them out again and moved his lips. In this way, he meant to say, "Bring me something to eat." But the waiter brought him a lot of things to (12) ______: first tea, then coffee, then milk, but no food. The Englishman was sorry that he was not able to tell the waiter he was hungry. He was eardy to leave the restaurant. When another man came in and put his hands on his stomach. And this sign was (13) ______ enough for the waiter. In a few minutes, the waiter brought him a large plate of bread and meat. At last, the Englishman had his meal in the same way.Điền ô số 12
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks.When you wave to a friend, you are using sign language. When you smile at someone, you mean to be (9) ______. When you put one finger in front of your (10) ______, you mean, "Be quiet." Yet, people in different countries may use different sign languages. Once an Englishman was in Italy he could speak a little Italian. One day while he was walking in the street, he felt (11) ______ and went into a restaurant. When the waiter came, the Englishman opened his mouth, put his fingers into it and took them out again and moved his lips. In this way, he meant to say, "Bring me something to eat." But the waiter brought him a lot of things to (12) ______: first tea, then coffee, then milk, but no food. The Englishman was sorry that he was not able to tell the waiter he was hungry. He was eardy to leave the restaurant. When another man came in and put his hands on his stomach. And this sign was (13) ______ enough for the waiter. In a few minutes, the waiter brought him a large plate of bread and meat. At last, the Englishman had his meal in the same way.Điền ô số 11
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks.When you wave to a friend, you are using sign language. When you smile at someone, you mean to be (9) ______. When you put one finger in front of your (10) ______, you mean, "Be quiet." Yet, people in different countries may use different sign languages. Once an Englishman was in Italy he could speak a little Italian. One day while he was walking in the street, he felt (11) ______ and went into a restaurant. When the waiter came, the Englishman opened his mouth, put his fingers into it and took them out again and moved his lips. In this way, he meant to say, "Bring me something to eat." But the waiter brought him a lot of things to (12) ______: first tea, then coffee, then milk, but no food. The Englishman was sorry that he was not able to tell the waiter he was hungry. He was eardy to leave the restaurant. When another man came in and put his hands on his stomach. And this sign was (13) ______ enough for the waiter. In a few minutes, the waiter brought him a large plate of bread and meat. At last, the Englishman had his meal in the same way.Điền ô số 10
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks.When you wave to a friend, you are using sign language. When you smile at someone, you mean to be (9) ______. When you put one finger in front of your (10) ______, you mean, "Be quiet." Yet, people in different countries may use different sign languages. Once an Englishman was in Italy he could speak a little Italian. One day while he was walking in the street, he felt (11) ______ and went into a restaurant. When the waiter came, the Englishman opened his mouth, put his fingers into it and took them out again and moved his lips. In this way, he meant to say, "Bring me something to eat." But the waiter brought him a lot of things to (12) ______: first tea, then coffee, then milk, but no food. The Englishman was sorry that he was not able to tell the waiter he was hungry. He was eardy to leave the restaurant. When another man came in and put his hands on his stomach. And this sign was (13) ______ enough for the waiter. In a few minutes, the waiter brought him a large plate of bread and meat. At last, the Englishman had his meal in the same way.Điền ô số 9