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Câu hỏi:

02/07/2024 98

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?

A. Ship's crews 

Đáp án chính xác

B. Research engineers 

C. People with insomnia 

D. Engine repair teams 

Trả lời:

verified Giải bởi Vietjack

Đáp án A

Thông tin ở đoạn cuối: 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

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Câu 2:

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.

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Câu 3:

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.

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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.

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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________.

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Câu 4:

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.

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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________.

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Câu 5:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 6:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 7:

Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction.

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Câu 8:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

The woman________ last week has been freed by the police.

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Câu 9:

Mark the letter A, B, C, or D on your answer sheet to indicate the word that has underlined part pronounced differently from the rests.

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Câu 10:

Mark the letter A, B, C, or D to indicate the word or phrase that is CLOSEST in meaning to the underlined part in each of the following questions.

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Câu 11:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 12:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 13:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 14:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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Câu 15:

Mark the letter A, B , C, or D on your answer sheet to indicate the correct answer to each of the following questions.

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