Question

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

All the following are mentioned as possible factors in drawing insects to weakened trees EXCEPT ________ 

A. sounds 

B. changes in colours 

C. smells 

D. thermal changes 

Answer 1

Chọn B

Kiến thức: Đọc hiểu

Giải thích:

Tất cả những điều sau đây được đề cập đến như là những yếu tố có thể trong việc dẫn những con côn trùng đến cây bị suy yếu NGOẠI TRỪ ________.

  A. âm thanh                                               

B. thay đổi màu sắc

  C. ngửi                                                       

D. thay đổi nhiệt

Thông tin: 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.

Tạm dịch: Các nhà nghiên cứu hiện đang tiến hành các cuộc kiểm tra với những cây trong chậu đã bị rút hết nước để xem liệu âm thanh có phải là thu hút côn trùng hay không. Một nhà khoa học cho biết “Những cây thiếu nước cũng có mùi khác với các loại cây khác, và chúng sẽ bị thay đổi nhiệt, vì vậy côn trùng có thể phản ứng với một thứ gì đó khác với âm thanh”