托福考试2017阅读模拟冲刺题（十七）_第2页

　　6. Why is "plankton" mentioned in line 17?

　　(A) To demonstrate the interdependence of different species.

　　(B) To emphasize the importance of food resources in preventing mass extinction.

　　(C) To illustrate a comparison between organisms that live on the land and those that live in the ocean.

　　(D) To point out that certain species could never become extinct.

　　7. According to paragraph 2, evidence from fossils suggests that

　　(A) Extinction of species has occurred from time to time throughout Earth's history.

　　(B) Extinctions on Earth have generally been massive

　　(C) There has been only one mass extinction in Earth's history.

　　(D) Dinosaurs became extinct much earlier than scientists originally believed.

　　8. The word "finding" in line 20 is closest in meaning to

　　(A) published information

　　(B) research method

　　(C) ongoing experiment

　　(D) scientific discovery

　　9. Which of the following can be inferred about the theory mentioned in Line 21-23?

　　(A) Many scientists could be expected to disagree with it.

　　(B) Evidence to support the theory has recently been found.

　　(C) The theory is no longer seriously considered.

　　(D) Most scientists believe the theory to be accurate.

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

　　(A) It reflects the interrelationship of many species.

　　(B) It may depend on chance events.

　　(C) It does not vary greatly from species to species

　　(D) It is associated with astronomical conditions.

　　11. According to the passage , it is believed that the largest extinction of a species occurred

　　(A) 26 million years ago

　　(B) 65 million years ago

　　(C) 225 million years ago

　　(D) 250 million years ago

　　参考答案：BCDCD AADAB C