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 is estimated that over 99 percent of all species that have 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 became extinct at the same time- a mass extinction. One of the best-known examples of mass extinction occurred 65 mmion 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 approximately 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, affecting even organisms not living in the oceans. 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 intensive 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 or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.
Which of the following can be inferred from the theory of periodic extinction mentioned in paragraph 3?
A. The theory is no longer seriously considered
B. Many scientists could be expected to disagree with it
C. Most scientists believe the theory to be accurate
D. Evidence to support the theory has recently been found
Kiến thức: Đọc hiểu
Giải thích:
Điều nào sau đây có thể được suy ra từ lý thuyết tuyệt chủng định kỳ được đề cập trong đoạn 3?
A. Lý thuyết không còn được xem xét nghiêm túc
B. Nhiều nhà khoa học có thể sẽ không đồng ý với nó
C. Hầu hết các nhà khoa học tin rằng lý thuyết này là chính xác
D. Bằng chứng để hỗ trợ lý thuyết gần đây đã được tìm thấy
Thông tin: The 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…
Tạm dịch: Sự tuyệt chủng tuần hoàn này có thể do sự giao nhau của quĩ đạo trái đất với một đám mây của sao chổi, nhưng lý thuyết này hoàn toàn chỉ là suy đoán. Một số nhà nghiên cứu cũng suy đoán rằng sự tuyệt chủng này có thể xảy ra một cách ngẫu nhiên.
Chọn B
Dịch bài đọc:
Ước tính được rằng, có khoảng hơn 99 phần trăm các loài sinh vật đang tồn tại có nguy cơ tuyệt chủng. Vậy cái gì gây ra sự tuyệt chủng ấy ? Khi một loài không còn thích nghi được với sự biến đổi của môi trường, nó có thể sẽ chết. Nguyên nhân chính xác cho cái chết của chúng là do sự biến đổi từ môi trường này sang môi trường khác. Hệ sinh thái thay đổi nhanh chóng có thể khiến cho môi trường chống lại loài sinh vật. Ví dụ như, nhiệt độ thay đổi và sinh vật không thích ứng được. Nguồn thức ăn có thể bị ảnh hưởng bởi sự thay đổi môi trường, điều đó sẽ gây ra những vấn đề cho nhu cầu thức ăn của loài. Những loài khác có thể thích ứng tốt hơn,với môi trường, dẫn đến sự cạnh tranh, và cuối cùng, gây ra cái chết của cả một loài sinh vật..
Các mẫu hóa thạch cho thấy rằng sự tuyệt chủng đã xảy ra trong suốt lịch sự của trái đất. Những nghiên cứu gần đây cũng tiết lộ rằng trong một số trường hợp, nhiều loài đã tuyệt chủng cùng một lúc- sự tuyệt chủng hàng loạt. Một minh chứng rõ nhất được biết đến cho sự tuyệt chủng hàng loạt đã xảy ra cách đây 65 triệu năm với sự diệt vong của loài khủng long và nhiều loài khác. Có lẽ sự tuyệt chủng hàng loạt lớn nhất là xảy ra cách đây 225 triệu năm, khi mà gần như 95 phần trăm các loài sinh vật đã chết. Những sự tuyệt chủng hàng loạt có thể gây ra bởi sự thay đổi tương đối nhanh chóng của môi trường và có thể tồi tệ hơn bởi mối liên hệ mật thiết giữa các loài. Ví dụ như, nếu xảy ra sự tiêu diệt hầu hết các loài sinh vật nhỏ dưới đại dương, thì hàm lượng oxy sẽ giảm, thậm chí tác động làm các loài sinh vật sẽ không sống dưới đại dương nữa. Sự thay đổi như thế hầu như chắc chắn sẽ dẫn đến tuyệt chủng hàng loạt. .
Một phát hiện thú vị và gây ra tranh cãi đã chỉ ra rằng sự tuyệt chủng trong suốt 250 triệu năm qua có xu hướng gia tăng 26 triệu mỗi năm. Sự tuyệt chủng tuần hoàn này có thể do sự giao nhau của quĩ đạo trái đất với một đám mây của sao chổi, nhưng lý thuyết này hoàn toàn chỉ là suy đoán. Một số nhà nghiên cứu cũng suy đoán rằng sự tuyệt chủng này có thể xảy ra một cách ngẫu nhiên. Điều đó có nghĩa là, một số loài có thể bị loại bỏ và những loài khác có thể vẫn tồn tại mà không có một nguyên do rõ ràng nào cả. Sự sống của một loài sẽ không phụ thuộc vào khả năng có thể thích ứng được hay không của chúng. Do đó, một vài sự tiến hóa lịch sử có thể chính là sự phản ánh các sự kiện có bản chất ngẫu nhiên diễn ra liên tiếp.
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.
They have been forced to live in marginal environments, such as deserts and arctic wastelands.
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
In the twentieth - century, people depend on unlimited energy to power their everyday lives. A wide range of energy-run devices and modern conveniences are taken for granted, and although it may seem that we will never be in danger of living without those conveniences, the fact is that many supplies of energy are dwindling rapidly. Scientists are constantly searching for new sources of power to keep modern society running. Whether future populations will continue to enjoy the benefits of abundant energy will depend on the success of this search.
Coal, oil, and natural gas supply modern civilization with most of its power. However, not only are supplies of these fuels limited, but they are a major source of pollution. If the energy demands of the future are to be met without seriously harming the environment, existing alternative energy sources must be improved or further explored and developed. These include nuclear, water, solar, wind, and geothermal power, as well as energy from new, nonpolluting types of fuels. Each of these alternatives, however, has advantages and disadvantages.
Nuclear power plants efficiently produce large amounts of electricity without polluting the atmosphere; however, they are costly to build and maintain, and they pose the daunting problem of what to do with nuclear waste. Hydroelectric power is inexpensive and environmentally safe, but impractical for communities located far from moving water. Harnessing energy from tides and waves has similar drawbacks. Solar power holds great promise for the future but methods of collecting and concentrating sunlight are as yet inefficient, as are methods of harnessing wind power.
Every source of energy has its disadvantages. One way to minimize them is to use less energy. Conservation efforts coupled with renewable energy resources, such as a combination of solar, water, wind, and geothermal energy and alternative fuels, such as alcohol and hydrogen, will ensure supplies of clean, affordable energy for humanity's future.
From the passage, it can be inferred that to solve our energy problems ________ .
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.
Though built almost five hundred years ago, the church remained practically intact.
Is it acceptable to touch ______ person on _______ shoulder in a conversation?
The Complex of Hue Monuments was the first site in Viet Nam ________ as a World Heritage Site by UNESCO.
Any pupil caught ________ was made to stand at the front of the class.
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.
Only during the nineteenth century did silent reading become commonplace.
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
In the twentieth - century, people depend on unlimited energy to power their everyday lives. A wide range of energy-run devices and modern conveniences are taken for granted, and although it may seem that we will never be in danger of living without those conveniences, the fact is that many supplies of energy are dwindling rapidly. Scientists are constantly searching for new sources of power to keep modern society running. Whether future populations will continue to enjoy the benefits of abundant energy will depend on the success of this search.
Coal, oil, and natural gas supply modern civilization with most of its power. However, not only are supplies of these fuels limited, but they are a major source of pollution. If the energy demands of the future are to be met without seriously harming the environment, existing alternative energy sources must be improved or further explored and developed. These include nuclear, water, solar, wind, and geothermal power, as well as energy from new, nonpolluting types of fuels. Each of these alternatives, however, has advantages and disadvantages.
Nuclear power plants efficiently produce large amounts of electricity without polluting the atmosphere; however, they are costly to build and maintain, and they pose the daunting problem of what to do with nuclear waste. Hydroelectric power is inexpensive and environmentally safe, but impractical for communities located far from moving water. Harnessing energy from tides and waves has similar drawbacks. Solar power holds great promise for the future but methods of collecting and concentrating sunlight are as yet inefficient, as are methods of harnessing wind power.
Every source of energy has its disadvantages. One way to minimize them is to use less energy. Conservation efforts coupled with renewable energy resources, such as a combination of solar, water, wind, and geothermal energy and alternative fuels, such as alcohol and hydrogen, will ensure supplies of clean, affordable energy for humanity's future.
It can be inferred from the passage that _______ .
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
We _______ in silence when he suddenly ________ me to help him.
We need _______ actions and interventions of the local authorities to prevent national parks from being destroyed by pollution.
Mark the letter A, B, C or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.
Next year, I have to decide which area of medicine I want to ________ in.
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 is estimated that over 99 percent of all species that have 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 became extinct at the same time- a mass extinction. One of the best-known examples of mass extinction occurred 65 mmion 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 approximately 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, affecting even organisms not living in the oceans. 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 intensive 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 or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.
The word "demise" in paragraph 2 is closest in meaning to _______ .