OG 10 57

supermanlee

57. Extinction is a process that can depend on a variety of ecological, geographical, and physiological variables. These variables affect different species of organisms in different ways, and should, therefore, yield a random pattern of extinctions. However, the fossil record shows that extinction occurs in a surprisingly definite pattern, with many species vanishing at the same time.

Which of the following, if true, forms the best basis for at least a partial explanation of the patterned extinctions revealed by the fossil record? b

(A) Major episodes of extinction can result from widespread environmental disturbances that affect numerous different species.

(B) Certain extinction episodes selectively affect organisms with particular sets of characteristics unique to their species.

(C) Some species become extinct because of accumulated gradual changes in their local environments.

(D) In geologically recent times, for which there is no fossil record, human intervention has changed the pattern of extinctions.A

(E) Species that are widely dispersed are the least likely to become extinct.

57.

Choice A, the best answer, asserts that some environmental disturbances can be so widespread as to cause the extinction of numerous species. This fact helps to explain why the fossil record frequently shows many species becoming extinct at the same time, despite the variety of factors that can cause a species to become extinct.



None of the other choices explain how numerous extinctions could have occurred simultaneously in the past. Choice B explains why sometimes only a very limited range of species become extinct. Choice C explains how some individual species become extinct. Choice D explains why the modern period is unlike the period of the fossil record, and choice E states which species are least likely to become extinct.


已经搜索过了。

我的疑问是题目中说These variables affect different species of organisms in different ways, and should, therefore, yield a random pattern of extinctions. However, the fossil record shows that extinction occurs in a surprisingly definite pattern, with many species vanishing at the same time.


而答案A中说affect numerous different species.并没有说他们extinct方式是definite pattern. 这样一来没有理由相信widespread environmental disturbances 会让多种动物的死法一样啊。

我选的是B，selectively affect organisms with particular sets of characteristics unique to their species.    with particular sets of characteristics unique to their species,说明只影响了有同样特征的动物，这样一来才能保证死掉的动物按一种死法啊。OG解释里只说Choice B explains why sometimes only a very limited range of species become extinct。

难道这道题要按题目中提到的many来选？因为A中有majority,而B中有particular,可particular并不代表一定数量就少吧。

请NN们指点！

fly12404

, forms the best basis for at least a "partial "explanation of the patterned extinctions revealed by the fossil record?
問可部分解釋化石為什麼反映出來不同
化石是說會一次死很多物種
(B) Certain extinction episodes "selectively" affect organisms with particular sets of characteristics unique to their species.
b說選擇性的死 , 與化石所呈現不同 無法解釋

supermanlee

感谢台北的朋友。
selectively不能是patterned的吗？selective extinction的结果不就是具有共性的动物死掉吗？
化石反应的不就是patterned的死亡吗？

问题中说at least 部分解释原因，既然是部分解释的话，A倒是可以作为答案，哪怕它没有说明为什么是patterned的死亡。