A New GWD CR

Whales originated in the freshwater lakes and rivers of ancient Asia about sixty million years ago. Not until 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 logically supported by the information given?

题目说Whales600万年前起源于亚洲，但是只有到500万年前，才有些Whales的kidney develop 到可以喝盐水，虽然化石显示在早期（可能早于500万年前）没有这种肾的鲸鱼也可以到海里游泳，但是，必须频繁的返回到淡水河饮水。

因为起源亚洲，且没有这种肾（500万年前），而即使能在海里游泳的因频繁的返回到淡水河饮水而无法走远，那么，其他on continents that were at the time separated from ancient LACE w:st="on">AsiaLACE> by wide expanses of ocean.肯定不会有Whales。所以，a是答案。