急问GWD17-Q34没搜到明确的讨论答案

34. GWD17-Q34:

During the month of May, crabs arrive on Delaware’s beaches to lay eggs.  Certain shorebirds depend on these eggs for food during their annual spring migration to their northern breeding grounds.  Delaware’s crab population has declined recently.  This decline, however, poses no serious threat to the migrating shorebird populations:  by remaining longer in Delaware, the birds will be able to eat enough crab eggs to allow them to complete their migration.

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

A.      No other food available to the birds on Delaware’s beaches is as nutritious and accessible as are crab eggs.

B.      The decline in the number of crabs on Delaware’s beaches is due to the harvesting of crabs by humans.

C.      There are more crabs on Delaware’s beaches than in any other area that the migrating birds pass through.

D.      The crabs do not conceal their eggs.

E.       The earlier in the season the shorebirds complete their migration, the more likely they are to breed successfully.

-------------------------------------------------------------------------------------B--
            E----------------

我选B因为想说即使鸟呆的时间长也没用，没有crab egg可以吃

看到答案是E，觉得提干要削弱的是complete their migration，至于breed那是migration之后的事儿，觉得有无关的嫌疑。。。。

请NN指点啊。。。。就要考了，好急。。。

原文：因果关系，“因为鸟在D呆的时间长能够吃到足够的蛋，所以数量不受到威胁。”

思路：削弱，原因不成立。

有了这个思路你就知道出题者本题的考点在“鸟在D呆的时间长”这个原因不成立。E体现了时间概念，早走早好，即削弱呆时间长这个原因。