Câu hỏi:
01/04/2020 1,584Mark the letter a, B, C, or D on your answer sheet to indicate the sentence that is closest meaning to each of the following questions or indicate the correct answer to each of them from 1 to 7
It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food resources may be affected by environmental changes, which will then cause problems for a species requiring these resources. Other species may become better adapted to an environment, resulting in competition and, ultimately, in the death of a species.
The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species become extinct at the same time- a mass extinction. One of the best- known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life. Perhaps the largest mass extinction was the one that occurred 225 million years ago, when appropriately 95 percent of all species died. Mass extinction can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the ocean. Such a change would probably lead to a mass extinction.
One interesting, and controversial, finding is that extinctions during the past 250 million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated that extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.
According to the passage, it is believed that the largest extinction of a species occurred
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Trả lời:
Đáp án D
Theo đoạn văn, người ta tin rằng sự tuyệt chủng lớn nhất của một loài xảy ra vào:
A. 250 triệu năm trước
B. 225 triệu năm trước
C. 65 triệu năm trước
D. 26 triệu năm trước.
Dẫn chứng ở câu thứ 4 đoạn 2: “Perhaps the largest mass extinction was the one that occurred 225 million years ago” – ( Sự tuyệt chủng lớn nhất của 1 loài có lẽ đã xảy ra vào 225 triệu năm trước).
CÂU HỎI HOT CÙNG CHỦ ĐỀ
Câu 1:
Mark the letter A, B, C, or D on your answer sheet to complete the sentence.
John: “Do you think that we should use public transportation to protect our environment?”
Mary: “____________”
Câu 2:
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest meaning to the given sentence.
It’s possible that he didn’t hear what I said
Câu 3:
Linda insisted that the newly- born baby ___________after her husband’s father.
Câu 5:
My father is fond of sport. He goes to the Sport Clubs to watch________every Saturday.
Câu 6:
There were many large rooms with _________walls in the castle.
Câu 7:
Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction.
Bacteria lived in the soil play a vital role in recycling the carbon and nitrogen needed by plants.
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