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 to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

According to paragraph 2, evidence from fossils suggests that

A. extinctions on Earth have generally been massive

B. dinosaurs became extinct much earlier than scientists originally believed

C. there has been only one mass extinction in Earth's history

D. extinction of species has occurred from time to time throughout Earth's history

1
23 tháng 4 2017

Đáp án D

Dịch nghĩa: Theo đoạn 2, những hóa thạch cho thấy rằng _____________.

A. tuyệt chủng trên trái đất đang tăng dần.

B. khủng long tuyệt chủng sớm hơn nhiều so với các nhà khoa học đã từng tin tưởng.

C. mới chỉ có một lần tuyệt chủng hàng loạt trong lịch sử trái đất.

D. sự tuyệt chủng xảy ra suốt chiều dài lịch sử trái đất.

Giải thích: Thông tin nằm ở “The fossil record reveals that extinction has occurred throughout the history of Earth”

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary 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. many scientists could be expected to disagree with it.

B. most scientists believe the theory to be accurate.

C. the theory is no longer seriously considered.

D. evidence to support the theory has recently been found

1
20 tháng 8 2019

Đáp án A

Dịch nghĩa: Từ học thuyết tuyệt chủng chu kì được đề cập ở đoạn 3 có thể suy ra điều gì?

A. rất nhiều nhà khoa học có thể phản đối nó.

B. hầu hết các nhà khoa học tin học thuyết này là đúng.

C. học thuyết này không còn được xem xét một cách nghiêm túc nữa.

D. bằng chứng để ủng hộ học thuyết này đã được tìm ra.

Giải thích: Thông tin nằm ở “The periodic extinction might be due to intersection of the earth’s orbit with a cloud of comets, but this theory is purely speculative”. Vì nó hoàn toàn là suy đoán nên ta có thể suy đoán rằng nó bị nhiều nhà khoa học khác phản đối.

 Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

 

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

In paragraph 3, the author makes which of the following statements about a species' survival?

 

A. it may depend on chance events.

B. it does not vary greatly from species to species

C. it reflects the interrelationship of many species.

D. it is associated with astronomical conditions.

1
18 tháng 12 2018

Đáp án A

Dịch nghĩa: Ở đoạn 3, tác giả nói gì về sự tồn tại của một loài?

A. Nó có thể phụ thuộc vào những việc xảy ra tình cờ.

B. Nó không khác nhau nhiều giữa các loài.

C. Nó phản ánh mối liên hệ giữa các loài.

D. Nó liên quan đến điều kiện thiên văn học.

Bài dịch

Người ta ước tính rằng hơn 99 phần trăm tất cả các loài từng tồn tại đã bị tuyệt chủng. Điều gì gây ra sự tuyệt chủng? Khi một loài không còn thích nghi với môi trường đã thay đổi, nó có thể biến mất. Các nguyên nhân chính dẫn đến một loài chết đi khác nhau đối với các trường hợp khác nhau. Sự thay đổi hệ sinh thái quá nhanh có thể khiến môi trường sống trở nên khó khăn với các loài đó. Ví dụ, nhiệt độ có thể thay đổi mà một loài không thể thích nghi. Nguồn thức ăn có thể bị ảnh hưởng bởi những thay đổi của môi trường, sau đó sẽ tiếp tục gây ra những vấn đề khác cho loài mà cần sử dụng nguồn thức ăn này. Các loài khác có thể thích nghi tốt hơn với môi trường, dẫn đến sự cạnh tranh và cuối cùng, là cái chết của một loài nào đó.

Các mẫu hóa thạch cho thấy rằng sự tuyệt chủng đã xảy ra trong suốt lịch sử của trái đất. Phân tích gần đây cũng tiết lộ rằng trong một số trường hợp nhiều loài đã tuyệt chủng cùng lúc - tuyệt chủng hàng loạt. Một trong những ví dụ nổi bật nhất của tuyệt chủng hàng loạt xảy ra vào 65 triệu năm trước đây với sự sụp đổ của khủng long và nhiều sinh vật sống khác. Có lẽ lần tuyệt chủng hàng loạt lớn nhất xảy ra vào 225 triệu năm trước đây, khi khoảng 95 phần trăm số loài đã chết. Tuyệt chủng hàng loạt có thể bị gây ra bởi sự thay đổi tương đối nhanh chóng của môi trường và có thể trở nên tồi tệ hơn bởi các mối liên hệ mật thiết giữa các loài. Ví dụ, nếu một điều gì đó đã xảy ra và tiêu diệt nhiều sinh vật phù du trong các đại dương, sau đó hàm lượng oxy của trái đất sẽ giảm, thậm chí ảnh hưởng đến các sinh vật không sống trong đại dương. Một sự thay đổi như vậy có thế sẽ dẫn đến sự tuyệt chủng hàng loạt.

Một khám phá thú vị, và cũng gây nhiều tranh cãi, đó là sự tuyệt chủng trong suốt 250 triệu năm qua đã có xu hướng tăng mạnh mẽ hơn sau mỗi 26 triệu năm. Sự tuyệt chủng có chu kỳ này có thể là do giao điểm của quỹ đạo trái đất với một đám mây sao chổi, nhưng thuyết này hoàn toàn chỉ là suy đoán. Một số nhà nghiên cứu cũng đã cho rằng sự tuyệt chủng thường là ngẫu nhiên. Nghĩa là một số loài bị loại bỏ và những loài khác có thể tiếp tục tồn tại mà không có lý do cụ thể nào. Sự tồn tại của một loài có thể không liên quan gì đến khả năng thích nghi hay không thích nghi của chúng. Nếu vậy, một vài sự tiến hóa lịch sử có thể phản ánh một chuỗi các sự kiện ngẫu nhiên quan trọng.

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

What does the author say in paragraph 1 regarding most species in Earth's history?

A. they have remained basically unchanged from their original forms.

B. they are no longer in existence.

C. they have been able to adapt to ecological changes.

D. they have caused rapid change in the environment

1
1 tháng 12 2019

Đáp án B

Dịch nghĩa: Tác giả nói gì về phần lớn các loài động vật trong lịch sử trái đất ở đoạn l?

A. Chúng gần như không thay đổi gì so với thời xưa.

B. Chúng không còn tồn tại.

C. Chúng đã thích nghi với sự thay đổi sinh thái.

D. Chúng gây ra những thay đổi nhanh chóng đến môi trường.

Giải thích: Thông tin nằm ở “It is estimated that over 99 percent of all species that ever existed have become extinct”.

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

he word "ultimately" is closest meaning to __________.

A. dramatically

B. unfortunately

C. eventually

D. exceptionally

1
12 tháng 11 2018

Đáp án C

Dịch nghĩa: Từ “ultimately” - cuối cùng - gần nghĩa nhất với __________.

A. đáng kể   B. không may        C. cuối cùng          D. ngoại trừ

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

The word "it" refers to ___________.

A. extinction 

B. species

C. 99 percent  

D. environment

1
8 tháng 12 2018

Đáp án B

Dịch nghĩa: Từ “it” nhắc tới ___________.

A. sự tuyệt chủng           B. loài                            C. 99%                   D. môi trường

Giải thích: Thông tin nằm ở “When a species is no longer adapted to a changed environment, it may perish” - Khi một loài không còn thích nghi với môi trường đã thay đổi, nó sẽ biến mất. Như vậy, nó ở đây chính là loài động vật đó.

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

The word "demise" is closest in meaning to ________.

A. change

B. help 

C. recovery

D. death

1
2 tháng 12 2018

Đáp án D

Dịch nghĩa: Từ “demise” - cái chết - gần nghĩa nhất với _________.

A. thay đổi   B. sự giúp đỡ        C. sự hồi phục       D. cái chết

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.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...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

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 adapted. 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 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 approximately 95 percent of all species died. Mass extinctions 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, even affect 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 intense every 26 million years. 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. 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 revolutionary history may reflect a sequence of essentially random events.

Why is "plankton" mentioned?

A. to illustrate a comparison between organisms that live on the land and those that live in the ocean

B. to point out that certain species could never become extinct.

C. to demonstrate the interdependence of different species

D. to emphasize the importance of food resources in preventing mass extinction.

1
23 tháng 7 2019

Đáp án C

Dịch nghĩa: Tại sao “plankton” - sinh vật phù du lại được đề cập?

A. để so sánh giữa những sinh vật sống trên cạn và sinh vật sống dưới biển

B. để chỉ ra rằng một số loài nhất định có thể sẽ không bao giờ tuyệt chủng

C. để chứng minh sự phụ thuộc lẫn nhau của các loài khác nhau

D. để nhấn mạnh sự quan trọng của nguồn thức ăn trong việc hạn chế tuyệt chủng hàng loạt

Giải thích: Thông tin nằm ở “. . .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, even alfect organisms not living in the oceans. Such a change would probably lead to a mass extinction” Tác giả nói về sự tuyệt chủng hàng loạt có thể gây ra bởi thay đổi môi trường sống, và sự phụ thuộc lẫn nhau khiến nó tệ hơn nữa. Sau đó, tác giả nói về việc các sinh vật phù du chết ảnh hưởng đến lượng oxy, rồi ảnh hưởng đến các loài không sống trong đại dương. Đây chính là mối liên hệ giữa các loài.

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 from 35 to 42.  Biological diversity has become widely recognized as a critical conservation issue only in the past two decades. The rapid destruction of the tropical rain forests, which are the ecosystems with the highest known species diversity on Earth, has awakened people to the importance and fragility of biological diversity. The high rate of species...
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 from 35 to 42.

  Biological diversity has become widely recognized as a critical conservation issue only in the past two decades. The rapid destruction of the tropical rain forests, which are the ecosystems with the highest known species diversity on Earth, has awakened people to the importance and fragility of biological diversity. The high rate of species extinctions in these environments is jolting, but it is important to recognize the significance of biological diversity in all ecosystems. As the human population continues to expand, it will negatively affect one after another of Earth’s ecosystems. In terrestrial ecosystems and in fringe marine ecosystems (such as wetlands), the most common problem is habitat destruction. In most situations, the result is irreversible. Now humans are beginning to destroy marine ecosystems through other types of activities, such as disposal and runoff of poisonous waste; in less than two centuries, by significantly reducing the variety of species on Earth, they have irrevocably redirected the course of evolution.

  Certainly, there have been periods in Earth’s history when mass extinctions have occurred. The extinction of the dinosaurs was caused by some physical event, either climatic or cosmic. There have also been less dramatic extinctions, as when natural competition between species reached an extreme conclusion. Only 0.01 percent of the species that have lived on Earth have survived to the present, and it was largely chance that determined which species survived and which died out.

          However, nothing has ever equaled the magnitude and speed with which the human species is altering the physical and chemical world and demolishing the environment. In fact, there is wide agreement that it is the rate of change humans are inflicting, even more than the changes themselves, that will lead to biological devastation. Life on Earth has continually been in flux as slow physical and chemical changes have occurred on Earth, but life needs time to adapt-time for migration and genetic adaptation within existing species and time for the proliferation of new genetic material and new species that may be able to survive in new environments.

According to the passage, natural evolutionary change is different from changes caused by humans in that changes caused by humans _____________ .

A. affect fewer ecosystems

B. are occurring at a much faster rate

C. are reversible

D. are less devastating to most species

2
14 tháng 9 2018

ĐÁP ÁN B

Đáp án : B

        ~ HOk tốt ~

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 from 35 to 42. Earth is richly supplied with different types of living organisms which co-exist in their environments, forming complex, interrelated communities. Living organisms depend on one another for nutrients, shelter, and other benefits. The extinction of one species can set off a chain reaction that affects many other species, particularly if the loss...
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 from 35 to 42.

Earth is richly supplied with different types of living organisms which co-exist in their environments, forming complex, interrelated communities. Living organisms depend on one another for nutrients, shelter, and other benefits. The extinction of one species can set off a chain reaction that affects many other species, particularly if the loss occurs near the bottom of the food chain. For example, the extinction of a particular insect or plant might seem inconsequential. However, there may be fish or small animals that depend on that resource for foodstuffs. The loss can threaten the survival of these creatures and larger predators that prey upon them. Extinction can have a ripple effect that spreads throughout nature. In addition to its biological consequences, extinction poses a moral dilemma for humans, the only species capable of saving the others. The presence of humans on the planet has affected all other life forms, particularly plants and animals. Human lifestyles have proven to be incompatible with the survival of some other species. Purposeful efforts have been made to eliminate animals that prey on people, livestock, crops, or pose any threat to human livelihoods. Some wild animals have been decimated by human desire for meat, hides, fur, or other body parts with commercial value. Likewise, demand for land, water, and other natural resources has left many wild plants and animals with little to no suitable habitat. Humans have also affected nature by introducing non-native species to local areas and producing pollutants having a negative impact on the environment. The combination of these human-related effects and natural obstacles such as disease or low birthrates has proven to be too much for some species to overcome. They have no chance of survival without human help. As a result, societies have difficult choices to make about the amount of effort and money they are willing to spend to save imperiled species. Will people accept limits on their property rights, recreational activities, and means of livelihood to save a plant or an animal? Should saving such popular species as whales and dolphins take priority over saving obscure, annoying, or fearful species? Is it the responsibility of humans to save every kind of life form from disappearing, or is extinction an inevitable part of nature, in which the strong survive and the weak perish? These are some difficult questions that people face as they ponder the fate of other species living on this planet.
(Source: http://www.encyclopedia.com)

Which of the following can result from the loss of one species in a food chain?

A. There might be a lack of food resources for some other species.

B. Animals will shift to another food chain in the community.

C. Larger predators will look for other types of prey.

D. The connections among the creatures in the food chain become closer.

1
31 tháng 10 2017

A. Đoạn 1, câu 3-6