问两道prep上的题，求解释！

wikywrx

21.    (28551-!-item-!-188;#058&003690)

Traces of cultivated emmer wheat have been found among the earliest agricultural remains of many archaeological sites in Europe and Asia.  The only place where the wild form of emmer wheat has been found growing is a relatively narrow strip of southwest Asia.  Since the oldest remains of cultivated emmer wheat yet found are from village sites in the same narrow strip, it is clear that emmer wheat was first domesticated somewhere in that strip.

Which of the following, if true, most strengthens the argument?

(A) The present-day distribution of another wild wheat, einkorn, which was also domesticated early in the development of agriculture, covers a much larger area of southwest Asia.
(B) Modern experiments show that wild emmer wheat can easily be domesticated so as to yield nearly as well as traditionally domestic strains.
(C) At the time when emmer wheat was first cultivated, it was the most nutritious of all the varieties of grain that were then cultivated.
(D) In the region containing the strip where wild emmer wheat has been found, climatic conditions have changed very little since before the development of agriculture.
(E) It is very difficult, without genetic testing, to differentiate the wild form of emmer wheat from a closely related wild wheat that also grows in southwest Asia.
这道直接不懂，跟天气有啥关系呀...

22.    (28829-!-item-!-188;#058&003748)

In the late 1980s, the population of sea otters in the North Pacific began to decline.  There are two plausible explanations for the decline:  predation, possibly by killer whales, or disease.  Of these two, disease is the more likely, since a concurrent sharp decline in populations of seals and sea lions is believed to have been caused by disease, and diseases that infect these creatures are likely to be able to infect sea otters also.

Which of the following, if true, most seriously weakens the reasoning?

(A) Killer whales in the North Pacific usually prey on seals and sea lions but will, when this food source is scarce, seek out other prey.
(B) There is no indication that the sea otter population at any North Pacific location declined in the 1980s because of substantial numbers of sea otters migrating to other locations.
(C) Along the Pacific coast of North America in the 1980s, sea otters were absent from many locations where they had been relatively common in former times.
(D) Following the decline in the population of the sea otters, there was an increase in the population of sea urchins, which are sea otters' main food source.
(E) The North Pacific populations of seals and sea lions cover a wider geographic area than does the population of sea otters.
我懂A的意思，但为什么不选C呢？
麻烦大家帮忙啊...我的逻辑实在太弱了，而且总是排除剩两个答案，然后选了个次的....

ljwqlcl881703

兰心寒 发表于 2013-11-20 23:19
说实话，我怎么也觉得是climatic condition一直没怎么变。不过我虽然这样认为，依然认为只能选D，这算是 ...

恩  后来我想通了 也就是你这意思  谢谢~~~

兰心寒

ljwqlcl881703 发表于 2013-11-20 20:05
有人能帮助么 求解

说实话，我怎么也觉得是climatic condition一直没怎么变。不过我虽然这样认为，依然认为只能选D，这算是典型的排它因作加强吧。
排除法排除其他无关选项上面都讨论过了。
至于D选项，我是这么理解的：wild E wheat只在某narrow strip被发现过，而最早的cultivated E wheat也在同地方被发现，怎样支持conclusion说E wheat就是在这个地方被最早培育的呢？
个人觉得加强题有几种很典型的方式，如果有gap，肯定是fill in the gap。如果逻辑链相对完整，一般有另两种方式，要么直接加强前提或者结论，要么排除他因，即说他因不会是造成结论，这个通常可以用取非来进行判断。
回到这题，climate一直没变，那这个地方由wild E wheat到cultivate E wheat就是很自然的过程。如果取非，climate变了，我们有理由相信wild E wheat就不适合生长了，那就要在别处适宜的地方培育E wheat再在这里栽种。不知道这样想对不对～

ljwqlcl881703

想明白了  哎 捉急的逻辑  太笨了~~~ 为了纠正错误 自己贴个自认为正确的推理：
那个strip  如果气候改变了  现在适合耕种 是因为气候的改变  使得EW 适应这里气候生长 最早可能在别的地方种植的 （其实感觉也能说是最早开始种植的，是从气候改变开始 依然是最早的）
         如果气候没改变  就说明 EW 在这里一直适应气候的生长 也就是最早家养 EW的地方~~

ljwqlcl881703

有人能帮助么 求解

ljwqlcl881703

这里不是说  1.发现最早家养EW   2.发现了最早家养EW遗留物   3.发现了唯一野生的EW     
然后从野生  到  家养 需要一定的时间  （就是3L解释所用的常识）我是这么理解的 - -
如果在这个时间里  气候变了    这个地方不适合野生了   别的地方适合了  就在别的地方  实现了家养  所以这里就不是第一次家养的地方
这是我的推理  我有个疑问 背景2中：说了发现这里有家养EW的遗留物 （比如：家养所用的器具之类的） 不就能说明 这里曾经就是第一次家养的地方么  而且题干中用了the oldest remians  ？？
求助~~~

ljwqlcl881703

怎么说道天气气候改善了呢？？？ D不是说 气候没怎么改善么 就是没变  你们都怎么看明白了  我怎么不能豁了个然开朗呢

微岚reflection

cycgundam 发表于 2012-9-8 08:44
第一道题可以简化理解为有一个驯养后的物种一般是被认为存在与欧洲与亚洲，但曾经发现这个物种在被驯养前在 ...

赞~~~好详细的解释，豁然开朗^^

j85258

cycgundam 发表于 2012-9-8 08:44
第一道题可以简化理解为有一个驯养后的物种一般是被认为存在与欧洲与亚洲，但曾经发现这个物种在被驯养前在 ...

豁然开朗的感觉

ccjiby

刚刚在做的时候有点不解，看到这个解答感觉明白了~谢谢！