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标题: 请教一道support 题 [打印本页]

作者: nanisoga 时间: 2010-7-5 19:44
标题: 请教一道support 题

22. GWD18-Q22:

Whales originated in the freshwater lakes and rivers of ancient Asia about sixty million years ago.Not until about ten million years later did species of whales develop specialized kidneys enabling them to drink salt water.Although fossil evidence shows that some early whale species that lacked such kidneys sometimes swam in the Earth’s saltwater oceans, these species must have had to return frequently to freshwater rivers to drink.

Which of the following is most strongly supported by the information given?

A.Fossils of whale species dating from between sixty million and fifty million years ago will not be found on continents that were at the time separated from ancient Asia by wide expanses of ocean.

B.Among whale fossils that date from later than about fifty million years ago, none are fossils of whale species that drank only fresh water.

C.Fossils of whale species that drank fresh water will not be found in close proximity to fossils of whale species that drank salt water.

D.The earliest whales that drank salt water differed from fresh-water-drinking whales only in their possession of specialized kidneys.

E.Between sixty million and fifty million years ago, the freshwater lakes and rivers in which whales originated were gradually invaded by salt water.
为什么是A 啊，读的不是很懂

作者: nanisoga 时间: 2010-7-5 22:15

作者: stone-no 时间: 2014-3-31 22:07
原文意思简单，就是说whale起源于60年的清水，十年后才有适应盐水的肾。证据表明早起的whale在盐水里经常会回去淡水区喝水。解释倒着说吧
E：60到50年前这个区间，盐水侵略他们的起源，原文没提
D：最早喝盐水的whale跟喝清水的whale的唯一区别是特殊的肾，唯一没有说吧
C：喝清水的跟喝盐水的没有近亲关系，拜托，喝盐水的就是由喝清水的进化过来的
B：在50年前的那个时间的之后（date later than 50m y ago)，没有只喝清水的whale，时间范围超出原文就可以排除了，原文也没有说是不是肾进化了就只喝盐水
A：这么看，60到50年前，XXX没有被发现。XXX代表：化石在被海洋从亚洲分割出来的大陆出现。XXX原文是没提过的，但是A选项的意思就是XXX没提过，那A是对的。

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