Read the following passage and mark the letter A, B, C ,or D on your answer sheet to indicate the correct answer for each of the questions.
Many ants forage across the countryside in large numbers and undertake mass migrations; these activities proceed because one ant lays a trail on the ground for the others to follow. As a worker ant returns home after finding a source of food, it marks the route Line by intermittently touching its stinger to the ground and depositing a tiny amount of trail pheromone – a mixture of chemicals that delivers diverse messages as the context changes.
These trails incorporate no directional information and may be followed by other ants in either direction. Unlike some other messages, such as the one arising from a dead ant, a food trail has to be kept secret from members of other species. It is not surprising then that ant species use a wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana calculated that one milligram of this substance would suffice to lead a column of ants three times around Earth.
The vapor of the evaporating pheromone over the trail guides an ant along the way, and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail, in what is called a vapor space. In following the trail, the ant moves to the right and left, oscillating from side to side across the line of the trail itself, bringing first one and then the other antenna into the vapor space. As the ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes it to swing to the left, and the ant then pursues this new course until its right antenna reaches the vapor space. It then swings back to the right, and so weaves back and forth down the trail.
According to the passage, the highest amount of pheromone vapor is found
A. in the receptors of the ants
B. just above the trail
C. in the source of food
D. under the soil along the trail
Giải bởi qa.haylamdo.com
B
Theo đoạn văn, lượng pheromone cao nhất được tìm thấy
A. trong các thụ thể của kiến
B. ngay phía trên dấu vết
C. trong nguồn thức ăn
D. dưới đất dọc theo dấu vết
=> đáp án B
Thông tin: A trail pheromone will evaporate to furnish the highest concentration of vapor right over the trail
Dịch bài đọc:
Nhiều con kiến đi kiếm thức ăn với số lượng lớn và di cư nhiều; những hoạt động này diễn ra bởi một con kiến tạo ra một dấu vết trên mặt đất để những con khác đi theo. Khi một con kiến thợ trở về nhà sau khi tìm ra nguồn thức ăn, nó đánh dấu đường đi bằng chạm ngòi của nó ngắt quãng trên mặt đất và để một lượng pheromone nhỏ - một hỗn hợp các chất hóa học cung ứng các thông điệp đa dạng khi bối cảnh thay đổi. Những dấu vết này không kết hợp thông tin phương hướng và có thể được đi theo sau bởi các con kiến khác ở cả hai hướng.
Không giống như một số thông điệp khác, chẳng hạn như một thông điệp phát sinh từ một con kiến chết, một con đường kiếm ăn phải được giữ bí mật khỏi các loài khác. Không có gì đáng ngạc nhiên khi kiến sử dụng nhiều loại hợp chất như dấu vết pheromones. Kiến có thể rất nhạy cảm với những tín hiệu này. Các nhà điều tra làm việc với dấu vết pheromone của loài kiến cắn lá Atta texana tính toán rằng một miligam của chất này sẽ đủ để dẫn một dãy kiến đi ba lần vòng quanh Trái đất.
Hơi của pheromone bay hơi trên dấu vết sẽ dẫn một con kiến dọc theo con đường, và con kiến phát hiện ra tín hiệu này với các thụ thể trong ăngten của nó. Một dấu vết pheromone sẽ bay hơi để cung ứng nồng độ hơi cao nhất trên dấu vết, trong cái gọi là không gian hơi. Khi đi theo dấu vết, kiến di chuyển sang phải và trái, dao động từ bên này sang bên kia đường thẳng của dấu vết, đưa ăngten đầu tiên và sau đó là ăngten khác vào không gian hơi. Khi con kiến di chuyển sang phải, ăng ten bên trái của nó sẽ đến không gian hơi. Các tín hiệu nhận được làm cho nó ngoặt sang trái, và con kiến phía sau đó theo cách này cho đến khi các ăng-ten bên phải của nó đến không gian hơi. Sau đó nó quay về phía bên phải, và tới lui theo dấu vết
Choose the answer among A, B, C, D to complete each of the sentences below:
Up to now, the teacher _______ our class five tests.
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning
It started to rain at 2 o’clock and it is still raining.
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions
Caroline has worn her new yellow dress only once since she buys it.
Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges.
- Lisa: “Have you been able to reach Peter?” - Gina: “……………”
Choose the answer among A, B, C, D to complete each of the sentences below:
It was …… easy for him to learn baseball because he had been a cricket player.
Mark the letter A, B, C, or D to identify the word whose stress pattern is different from that of the other words in the same group
Mark the letter A, B, C, or D on you answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.
He is very intelligent. He can solve all the problems in no time
Mark the letter A, B, C, or D to identify the word whose stress pattern is different from that of the other words in the same group
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning
“I will pay back the money, Gloria.” Said Ivan.
Choose the word whose underlined part is pronounced differently from others
Choose the word whose underlined part is pronounced differently from others
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
Martin Luther King, Jf., is well- known for his work in civil rights and for his many famous speeches, among which is his moving “ I have a dream” speech. But fewer people know much about King’s childhood. M.L., as he was called, was born in 1929 in Atlanta, Georgia, at the home of his maternal grandfather. M.L.’s grandfather purchased their home on Auburn Avenue in 1909, twenty years before M.L was born. His grandfather allowed the house to be used as a meeting place for a number of organizations dedicated to the education and social advancement of blacks. M.L. grew up in the atmosphere, with his home being used as a community gathering place, and was no doubt influenced by it.
M.L.’s childhood was not especially eventfully. His father was a minister and his mother was a musician. He was the second of three children, and he attended all black schools in a black neighborhood. The neighborhood was not poor, however. Auburn Avenue was an area of banks, insurance companies, builders, jewelers, tailors, doctors, lawyers, and other businesses and services. Even in the face of Atlanta’s segregation, the district thrived. Dr. King never forgot the community spirit he had known as a child, nor did he forget the racial prejudice that was a huge barrier keeping black Atlantans from mingling with whites.
From the passage we can infer that:
Choose the answer among A, B, C, D to complete each of the sentences below:
I went to a restaurant last night. I was the ten thousandth customer, so my dinner was on the ......
Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions
He takes four paracetamol everyday, not knowing that will seriously damage his liver
Mark the letter A, B, C or D on your answer sheet to indicate the word or phrase that is closest in meaning to the underlined part in each of the following questions.
His new yacht is certainly an ostentatious display of his wealth.
