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标题: [求助] GWD-27-Q22 [打印本页]

作者: andylouis 时间: 2007-9-13 21:19
标题: [求助] GWD-27-Q22

1. GWD-27-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?

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.
Among whale fossils that date from later than about fifty million years ago, none are fossils of whale species that drank only fresh water.
Fossils of whale species that drank fresh water will not be found in close proximity to fossils of whale species that drank salt water.
The earliest whales that drank salt water differed from fresh-water-drinking whales only in their possession of specialized kidneys.
Between sixty million and fifty million years ago, the freshwater lakes and rivers in which whales originated were gradually invaded by salt water.

A 看了几遍理解不来

希望nn 解答

作者: qincong83 时间: 2007-10-8 19:06

http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=1924812&id=205656&skin=0

2楼哥哥有精彩解答

作者: elaine1031 时间: 2009-7-20 17:27
up

作者: elaine1031 时间: 2009-7-20 19:00
up

作者: wangchen0355 时间: 2009-8-3 16:59
1

作者: 流浪的心 时间: 2010-9-19 16:11
题目的意思是：

6kw年前 whales喝淡水，1kw年之后（就是5kw年）前，开始长kidney可以喝海水了，然后问下面哪个一个被上文所支持（就是通过原文可以推出哪个）

选A
A是说在6kw年前和5kw年前的whales的化石不会在某些大陆上发现，这些大陆当时和古亚洲之间被海洋隔开

因为那段时间的whales还没有kidney 所以只能喝淡水所以生活在淡水区中

不知道这样说理解不？

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