[讨论]GWD27-22

hsyeng

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?

1. 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.
2. Among whale fossils that date from later than about fifty million years ago, none are fossils of whale species that drank only fresh water.
3. Fossils of whale species that drank fresh water will not be found in close proximity to fossils of whale species that drank salt water.
4. The earliest whales that drank salt water differed from fresh-water-drinking whales only in their possession of specialized kidneys.
5. Between sixty million and fifty million years ago, the freshwater lakes and rivers in which whales originated were gradually invaded by salt water.

答案給A請大家幫忙解答~

caterpillarcn

只喝淡水的鲸鱼可以到海里，但是要回去淡水里喝水，所以就不可以在海里呆太久。
因为鲸鱼是在asia起源的，所以在他们能靠海水生活之前，他们不可能出现在其他和asia被海隔开的大州上，游不过去嘛，会干死的。A中就给出了这个信息。

hsyeng

原來我忽略了 of ancient asia 這部分 謝啦 

xiaowan

A说的是化石不会存在于那个时期被ocean分开的亚洲大陆上，也许分开的两部分或多部分上都有淡水湖啊，鲸不用从海里游啊，原本就在那个大陆上的嘛

咦～～刚发现A有歧义哦～

1化石不会存在于在那一时期被大洋隔开的与亚洲大陆不同的另外的大陆上

2不存在于由大洋从亚洲大陆分离出来的另一个大陆上
             

怎么会这样？哪里理解错了？？

[此贴子已经被作者于2006-10-25 10:16:19编辑过]

smileday

i pick D.

choice D rules out the possibility that other organs of whales help whales to swim back.

lxzjojo

以下是引用xiaowan在2006-10-25 10:06:00的发言：

A说的是化石不会存在于那个时期被ocean分开的亚洲大陆上，也许分开的两部分或多部分上都有淡水湖啊，鲸不用从海里游啊，原本就在那个大陆上的嘛

咦～～刚发现A有歧义哦～

1化石不会存在于在那一时期被大洋隔开的与亚洲大陆不同的另外的大陆上

2不存在于由大洋从亚洲大陆分离出来的另一个大陆上
    

怎么会这样？哪里理解错了？？

即使分开的两部分上有淡水，但whale大佬们还是得从亚洲游到别的大陆上面啊！！注意，这里的continent是指除了ancient Asia之外的大陆！

heshaohua666

caterpillarcn,admiring very  much!!!!!!!!!!!!!!!!!!!!!!!!!!!!

llxx1985cn

up

s7s7

此题答案实际是在排除他因：鲸鱼六百万年前死了，肯定沉尸于亚洲大陆内陆，如果亚洲大陆分离漂移到南太平洋，那鲸鱼的六百万年前的fossil岂不是也到了南太平洋，这就无法判断，这六百万年前的鲸鱼到底喝盐水还是喝淡水了。

colorful_na

up