GWD逻辑请教--Whales originated in the freshwater lakes and rivers of ancient Asia ab

追梦的Yvonne · 发表于 2018-8-5 00:26:00

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.

答案是A，我觉得我有点不理解提议，能帮忙解释一下吗？

cycgundam · 发表于 2018-8-5 03:35:55

关键的premise是两个：

1，Whales originated in the freshwater lakes and rivers of ancient Asia about sixty million years ago. - 鲸鱼最早出现在6000万年的古亚洲大路上的淡水湖和河流里。

2，these species must have had to return frequently to freshwater rivers to drink. - 这些（淡水）生物必须时常从海里回到淡水区去饮水。

问题 - 以上题目（主要就上面两个premise）能总结出什么conclusion？

因为这些鲸鱼需要时常回到淡水区饮水，导致了他们不会离开淡水大陆太远，也无法长期在盐水海里生存。而因为他们是诞生在亚洲大陆，所以他们这一代不会离开亚洲大陆太远。故而在这群生物生存时间区间里（5000-6000万年前），这些鲸鱼不会出现在被盐水海所分割的另一块大陆上。

B不对因为违背题目的条件。题目的条件明确指出1000万年前鲸鱼的肾开始能够处理盐水，所以1000万年到B所提及的5000万年这段区间里，鲸鱼还是不能饮用盐水的。

C不对因为题目并没有提及能够处理盐水鲸鱼的活动区间。这些鲸鱼能否接近淡水水域我们并不清楚。我们清楚饮用淡水的鲸鱼还是能够去海里的（题目并没有否定），所以两种鲸鱼有没有交替题目并没有给出明显条件。

D不对在于这句话含义有明显的逻辑漏洞。诚然我们知道能够处理盐水的肾是这两种鲸鱼的差别。但是不是唯一差别我们并不清楚，题目并没有给出条件。

E不对在于题目并没有给出这方面的条件。淡水水域有没有被盐水入侵并不受到题目的支持或反对。我们只知道这些鲸鱼的变化，并不清楚淡水水域的变化。

追梦的Yvonne · 发表于 2018-8-5 12:07:23

cycgundam 发表于 2018-8-5 03:35
关键的premise是两个：

1，Whales originated in the freshwater lakes and rivers of ancient Asia about ...

看了你的翻译和详解，真的理解多了！谢谢

笛安 · 发表于 2018-12-13 21:49:33

cycgundam 发表于 2018-8-5 03:35
关键的premise是两个：

1，Whales originated in the freshwater lakes and rivers of ancient Asia about ...

谢谢！懂了！

GWD逻辑请教--Whales originated in the freshwater lakes and rivers of ancient Asia ab

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