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.
It’s a sound you will probably never hear, a sickened tree sending out a distress signal. But a group of scientists has heard the cries, and they think some insects also hear the trees and are drawn to them like vulture to a dying animal. Researchers with the US Department of Agriculture’s Forest Service fastened sensors to the bark of drought-stricken trees clearly heard distress calls. According to one of the scientists, most parched trees transmit their plight in the 50-hertz to 50-kilohertz range. (The unaided human ear can detect no more than 20 kilohertz). Red oak, maple, white pine, and birch all make slightly different sounds in the form of vibrations at the surface of the wood.
The scientists think that the vibrations are created when the water columns inside tubes that run along the length of the tree break, a result of too little water following through them. These fractured columns send out distinctive vibration pattems. Because some insects communicate at ultrasonic frequencies, they may pick up the trees' vibration and attack the weakened trees. Researchers are now running tests with potted trees that have been deprived of water to see if the sound is what attracts the insects. “Water-stressed trees also smell differently from other trees, and they experience thermal changes, so insects could be responding to something other than sound”, one scientist said
Which of the following is the main topic of the passage?
A. The sound made by trees
B. The vibrations produced by insects
C. The effect of insects on trees
D. The mission of the U.S Forest Service
Giải bởi qa.haylamdo.com
Chọn A
Kiến thức: Đọc hiểu
Giải thích:
Câu nào sau đây là chủ đề chính của đoạn văn?
A. âm thanh do cây cối tạo ra
B. sự rung động do côn trùng tạo ra
C. tác dụng của côn trùng trên cây.
D. nhiệm vụ của Sở Lâm nghiệp Hoa Kỳ
Thông tin: It’s a sound you will probably never hear, a sickened tree sending out a distress signal
Tạm dịch: Đó là một âm thanh mà bạn có thể sẽ không bao giờ nghe thấy, một cái cây bị bệnh gửi ra một tín hiệu đau khổ
_____ our own interests is one of the most important factors in choosing a job.
You should pay attention to _____ precautions of this machine before operating it
In today’s paper, it _____ that the Vietnam’s national examination for high school students will take palce from June 24th to 27th
Needless to say, Mike is cleverer than other students in the class
The accident brought him to his _____ and made him stop drinking
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.
It’s a sound you will probably never hear, a sickened tree sending out a distress signal. But a group of scientists has heard the cries, and they think some insects also hear the trees and are drawn to them like vulture to a dying animal. Researchers with the US Department of Agriculture’s Forest Service fastened sensors to the bark of drought-stricken trees clearly heard distress calls. According to one of the scientists, most parched trees transmit their plight in the 50-hertz to 50-kilohertz range. (The unaided human ear can detect no more than 20 kilohertz). Red oak, maple, white pine, and birch all make slightly different sounds in the form of vibrations at the surface of the wood.
The scientists think that the vibrations are created when the water columns inside tubes that run along the length of the tree break, a result of too little water following through them. These fractured columns send out distinctive vibration pattems. Because some insects communicate at ultrasonic frequencies, they may pick up the trees' vibration and attack the weakened trees. Researchers are now running tests with potted trees that have been deprived of water to see if the sound is what attracts the insects. “Water-stressed trees also smell differently from other trees, and they experience thermal changes, so insects could be responding to something other than sound”, one scientist said
The word “them” in the first paragraph refers to ______.
It was wrong of you not to ask your parents’ permission before deciding to quit your job
At first, it’s very difficult for the judge to identify the winner because the two runners seemed to cross the finishing line ______.
Janet is inviting Susan to go to the cinema.
- Janet: “Do you feel like going to the cinema this evening?”
- Susan: “_______.”
I still remember _____ off his extraordinary childhood with lots of hardship
Across the country, exam results have improved by an average of eight percentage
_____ his income of current job is relatively low, he finds it difficult to make ends meet.
75% of the world’s population habitually consume caffeine, which up to a point masks the symptoms of sleep deprivation
