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6 tháng 3 2021

A vacuum will neither conduct heat nor ...

A. transmit sound waves  B. transmitting sound waves  

C. sound waves are transmitted  D. the transmission of sound waves

 
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...
Đọc tiếp

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_________.

A. composing music 

B. repairing alarm systems

C. eliminating engine noises 

D. intensifying for warning sounds

1
2 tháng 12 2017

Đáp án C

Thông tin ở đoạn 1: 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.

=> microprocessor (bộ vi xử lý) được dùng để loại bỏ âm thanh

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...
Đọc tiếp

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_________.

A. cause deafness 

B. create hazardous working conditions 

C. influence ocean waves 

D. damage loudspeakers and sound equipment

1
10 tháng 9 2019

Đáp án B

Thông tin ở câu cuối: … which causes fatigue that can impair the efficiency and alertness of the crew, and may mask the warning sounds of alarm and fog signals.

(những âm thanh không mong muốn có thể gây mệt mỏi, ảnh hưởng đến năng suất và sự tỉnh táo của phi hành đoàn, và có thể che mất âm thanh cảnh báo và tín hiệu bão => tạo ra tình trạng làm việc nguy hiểm)

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...
Đọc tiếp

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_________.

A. the rising and falling of water in the ocean 

B. the crests and valleys of mountain ranges 

C. a flag waving in the air 

D. a machine for gauging air pressure 

1
30 tháng 3 2017

Đáp án A

Thông tin ở câu đầu tiên của bài đọc: Sound moves form its source to the ear by wavelike fluctuations in air pressure, something like the crests and troughs of ocean waves. (Âm thanh di chuyển hình thành nguồn gốc của nó trong tai bởi biến động trong áp suất không khí, một cái gì đó giống như các đỉnh và đáy của sóng biển.)

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...
Đọc tiếp

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?

A. To discuss a physical handicap

B. To warn about a growing danger 

C. To describe the structure of the ear 

D. To report on a new invention 

1
31 tháng 1 2017

Đáp án D

Mục đích của bài này là To report on a new invention (Giới thiệu một phát minh mới). Phát minh đó là sử dụng bộ vi xử lý (a microprocessor) để loại bỏ các âm thanh không mong muốn

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...
Đọc tiếp

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_________.

A. the nature of fog 

B. a way to improve alarm systems 

C. other causes of fatigue 

D. other uses for the microprocessor 

1
19 tháng 1 2017

Đáp án D

Bài đọc này chủ yếu nói về công dụng loại bỏ, tách âm thanh của bộ vi xử lý (a microprocessor). Vì vậy, đoạn sau của bài đọc này có thể sẽ nói về những công dụng khác của bộ vi xử lý này

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...
Đọc tiếp

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_________.

A. diverting people's attention from it

B. masking it with a louder noise 

C. canceling it out electronically 

D. removing its source

1
23 tháng 3 2019

Đáp án C

Thông tin ở câu thứ 2 và 3 của đoạn đầu tiên: One way to keep from hearing sound is to use ear plugs. Another way is to cancel out the sound with anti-sound. (Một cách để cách âm là sử dụng nút tai. Một cách nữa là triệt tiêu âm thanh với dụng cụ chống âm)

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...
Đọc tiếp

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 

B. Research engineers 

C. People with insomnia 

D. Engine repair teams 

1
28 tháng 2 2017

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

22 tháng 7 2017

Chọn đáp án B

Giải thích:

A. sáng tạo, sáng chế

B. khám phá

C. phát triển

D. tìm thấy

Dịch nghĩa: Bạn có biết ai là người khám phá ra sự thật rằng âm thanh có thể truyền qua sóng không?

8 tháng 2 2018

Đáp án B

A. sáng tạo, sáng chế

B. khám phá

C. phát triển

D. tìm thấy

Dịch nghĩa: Bạn có biết ai là người khám phá ra sự thật rằng âm thanh có thể truyền qua sóng không?