K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

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 effect of insects on trees

B. The vibrations produced by insects

C. The mission of the U.S Forest Service

D. The sounds made by trees

1
26 tháng 8 2018

Đáp án D

Câu nào sau đây là chủ đề chính của đoạn văn?

A. Tác động của côn trùng trên cây.

B. Sự rung động do côn trùng tạo ra.

C. Nhiệm vụ của Sở Lâm nghiệp Hoa Kỳ.

D. Những âm thanh được phát ra bởi bằng cây.

Thông tin ở câu chủ đề của đoạn văn: “It’s a sound you will probably never hear, a sickened tree sending out a distress signal” (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.)

Sau đó, tác giả nêu ra những nghiên cứu về âm thanh và những tín hiệu mà những cây bị suy yếu phát ra

=> Chủ đề chính của đoạn văn là những âm thanh được phát ra bởi bằng cây.

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...
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 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.

It can be inferred from the passage that research concerning the distress signals of trees  _________ . 

A. has been unproductive up to now

B. is no longer sponsored by the government

C. was conducted many years ago

D. is continuing

1
18 tháng 3 2019

Đáp án D

Có thể suy luận từ đoạn văn rằng các nghiên cứu liên quan đến tín hiệu đau khổ của cây _________.

A. đã không còn hiệu quả cho đến bây giờ

B. không còn được tài trợ bởi chính phủ

C. được thực hiện nhiều năm trước

D. đang tiếp tục

Thông tin ở câu: “Researchers are now running tests with potted trees that have been deprived of water to see if the sound is what attracts the insects.” (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 thứ thu hút côn trùng hay không.) => Tác giả dùng thì hiện tại tiếp diễn vì vậy các nghiên cứu đó vẫn còn đang diễn ra.

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...
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 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 could be considered a cause of the distress signals of trees?

A. attacks by insects

B. experiments by scientists

C. torn roots

D. lack of water

1
21 tháng 11 2017

Đáp án D

Vấn đề nào sau đây có thể được coi là nguyên nhân gây ra tín hiệu đau khổ của cây?

A. các cuộc tấn công bởi côn trùng

B. các thí nghiệm của các nhà khoa học

C. rễ bị đứt

D. thiếu nước

Thông tin ở câu: “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.” (Các nhà khoa học nghĩ rằng những rung động được tạo ra khi các cột nước bên trong các ống mà chạy dọc theo chiều dài của cây bị phá vỡ, là kết quả của việc quá ít nước chảy qua chúng.)

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...
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 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 could be considered a cause of the trees’ distress signals?

A. lack of water 

B. attacks by insects 

C. torn root 

D. experiments by scientists 

1
7 tháng 3 2017

Chọn A

Kiến thức: Đọc hiểu

Giải thích:

Điều nào sau đây có thể được coi là nguyên nhân gây ra tín hiệu đau khổ của cây?

  A. thiếu nước                                              B. bị côn trùng tấn công

  C. Rễ bị đứt                                                D. thí nghiệm của các nhà khoa học

Thông tin: 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.

Tạm dịch: Các nhà khoa học nghĩ rằng những rung động được tạo ra khi các cột nước bên trong các ống mà chạy dọc theo chiều dài của cây bị phá vỡ, là kết quả của việc quá ít nước chảy qua chúng.

Dịch bài đọc:

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. Nhưng một nhóm các nhà khoa học đã nghe thấy tiếng kêu khóc của chúng, và họ nghĩ rằng một số loài côn trùng cũng nghe thấy những cây cối và bị thu hút bởi chúng như một con kền kền với một con vật đang hấp hối. Các nhà nghiên cứu thuộc Sở lâm nghiệp Hoa Kỳ đã buộc cảm biến vào vỏ cây bị hạn hán và rõ ràng đã nghe thấy tiếng kêu đau khổ. Theo một trong các nhà khoa học, hầu hết các cây khô héo truyền tải tình trạng của chúng trong khoảng 50-hertz tới 50 kilohertz. (Tai người mà không có thiết bị trợ giúp chỉ có thể phát hiện âm thanh không quá 20 kilohertz). Sồi đỏ, gỗ phong, thông trắng, và bạch dương đều tạo ra những âm thanh hơi khác nhau dưới dạng rung động ở bề mặt gỗ.

Các nhà khoa học nghĩ rằng những rung động được tạo ra khi các cột nước bên trong các ống chạy dọc theo chiều dài của cây bị phá vỡ, là kết quả của việc quá ít nước chảy qua chúng. Những cột gãy nứt này tạo ra các kiểu rung động đặc biệt. Bởi vì một số loài côn trùng giao tiếp ở tần số siêu âm, chúng có thể phát hiện ra những rung động của cây và tấn công các cây bị suy yếu. 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 thứ 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”.

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...
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 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 

1
6 tháng 6 2017

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”

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...
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 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. thermal changes

B. sounds

C. changes in color

D. smells

1
21 tháng 6 2019

Đáp án C

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 trừ ________.

A. thermal changes: những thay đổi về nhiệt

B. sounds: những âm thanh

C. changes in color: những thay đổi trong màu sắc

D. smells: những mùi hương

Thông tin ở đoạn: “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.” (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.) => Tất ca các yếu tố có thể thu hút côn trùng ở những cây bị suy yếu bao gồm thermal changes, sounds và smells, tác giả không nhắc đến changes in color.

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...
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 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.

It can be inferred from the passage that the sounds produced by the trees ________ .

A. are the same no matter what type of tree produces them

B. cannot be heard by the unaided human ear

C. fall into the 1-20 kilohertz

D. serve as a form of communication among trees

1
19 tháng 2 2017

Đáp án B

Có thể suy ra từ đoạn văn rằng các âm thanh được tạo ra bởi cây ________.

A. tương tự cho dù là loại cây tạo ra chúng

B. không thể nghe thấy bằng tai người mà không có thiết bị trợ giúp.

C. rơi vào khoảng 1-20 kilohertz

D. làm việc như một hình thức giao tiếp giữa các cây

Thông tin ở câu: “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)” (Theo một trong các nhà khoa học, hầu hết các cây khô héo truyền tải tình trạng của chúng trong khoảng 50-hertz tới 50 kilohertz. (Tai người mà không có thiết bị trợ giúp chỉ có thể phát hiện âm thanh không quá 20 kilohertz.))

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...
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 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 “parched” in paragraph 1 is closest in meaning to  _________ .

A. dehydrated

B. recovered

C. damaged

D. burned

1
17 tháng 9 2019

Đáp án A

Từ “parched” trong đoạn 1 gần nghĩa nhất với ________ .

A. dehydrated (adj): mất nước

B. recovered (adj): hồi phục

C. damaged (adj): bị tổn thương

D. burned (adj): bị đốt cháy

parched (adj): khô héo ≈ dehydrated (adj)

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...
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 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 “parched” in paragraph 1 is closest in meaning to ______. 

A. recovered 

B. dehydrated 

C. burned 

D. damaged 

1
22 tháng 11 2017

Chọn B

Kiến thức: Từ đồng nghĩa

Giải thích:

Từ “parched” (khô héo) ở đoạn một có nghĩa gần nhất với từ _____.

  A. recovered (adj): hồi phục                      

B. dehydrated (adj): mất nước

  C. burned (adj): bị đốt cháy                       

D. damaged (adj): bị tổn thương

Thông tin: According to one of the scientists, most parched trees transmit their plight in the 50-hertz to 50-kilohertz range.

Tạm dịch: Theo một trong những nhà khoa học, hầu hết các cây khô đều lan truyền trạng thái của chúng trong phạm vi 50 hertz đến 50 kilohertz

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...
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 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 “plight” in paragraph 1 is closest in meaning to  ________ .

A. condition

B. cry

C. need

D. agony

1
9 tháng 7 2018

Đáp án A

Từ “plight” trong đoạn 1 gần nghĩa nhất với ________ .

A. condition (n): điều kiện, tình trạng

B. cry (n): tiếng khóc

C. need (n): nhu cầu

D. agony (n): sự đau khổ

plight (n): hoàn cảnh, trạng thái ≈ condition (n)