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. 答案是A,LZ做的时候没看清,A就跳过去了。解释意思是说,因为鲸鱼要喝淡水,所以游不过去大陆之间的咸水。 但是!但是!!但是!!!!大家有没有发现一个问题!!! 为什么!!!尼玛的!!鲸鱼的化石会在大陆上被发现啊!!尼玛鲸鱼不是鱼嘛!!在水里的啊!!ETS你这是在坑爹的吧!!!!!!!!1 -- by 会员 ivanbutterfly (2012/11/6 16:21:58)
If the whale didn't have the ability to drink salt water at that time, it was unable to survive in the ocean and thus it cannot migrate from Asia to other continents. Hope this helps. |