[求助]弱弱问下OG diagnostic test里CR26

jean1280

26.Gs are birds of Arctic regions.They feed on fish that gather beneath thin sheets of floating ice, and they nest on nearby land. Gs need  80 consecutive snow-free days in a year to raise their chicks, so until average temperatures in the Arctic began to rise recently,the Gs' range was limited to the southernmost Arctic coast. Therefore, if the warming continues, the Gs' range will probably be enlarged by being extended northward along the coast.

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

B.If the Arctic warming continues, Gs' current predators are likely to succeed in extending their own range farther north.

D.If the Artic warming continues, much of the thin ice in the southern Arctic will disappear.

答案是D 这个我知道，但是B怎么就没削弱呢？

predators的range enlarge了，那么Gs的range还能enlarge吗？那不就削弱了吗？有点不明白呀。。

谢谢NN指点此不才的女子！

bunny_piggy

做削弱题的时候相关是最重要的，你可以根据题目提出很多削弱的说法，但是往往只有一个是题目中说过的。D中冰没有了-》鱼没有了-》没有吃的了是题目中 有冰-》有吃的 的直接反对。

B虽然根据常识也可以判断为虚弱，可是，没有说G的天敌啊...无关地干活！

大胖

题目给出一个信息Gs吃fish （that gather beneath thin sheets of floating ice）

然后撇开上面的信息，谈温度对Gs 一个停留范围的影响，并从中推出结论。因此看选项之前，隐约感到选项会涉及到fish。

B乍一看削弱，实际为无关。 比如gs跑到北面几只，相应原来的predator也跟过去了一些，但不影响gs扩大范围。

jean1280

谢谢楼上的两位了！！