拜求教一道逻辑题，谢谢

Irene1221

11. GWD17-Q11:
Some species of Arctic birds are threatened by recent sharp increases in the population of snow geese, which breed in the Arctic and are displacing birds of less vigorous species.  Although snow geese are a popular quarry for hunters in the southern regions where they winter, the hunting season ends if and when hunting has reduced the population by five percent, according to official estimates.  Clearly, dropping this restriction would allow the other species to recover.

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

A.        Hunting limits for snow geese were imposed many years ago in response to a sharp decline in the population of snow geese.
B.        It has been many years since the restriction led to the hunting season for snow geese being closed earlier than the scheduled date.
C.        The number of snow geese taken by hunters each year has grown every year for several years.
D.        As their population has increased, snow geese have recolonized wintering grounds that they had not used for several seasons.
E.        In the snow goose’s winter habitats, the goose faces no significant natural predation.

答案给出的是B选项，我不明白这怎么是削弱呢？

maskloo

我理解的话：B 答案就是说 每年猎人都把总数的百分之五份额提前用完。snow geese的数量一直都控制。但不见得其他物种数量有提高。所以就说算打猎限制取消，其他物种数量也不一定提高

徐小黑

这个题的逻辑是这样子的
1.snow geese影响（减少）Arctic birds的数量
2.狩猎影响snow geese的数量
3.规定：狩猎在snow geese数量减少5%后停止
原文结论：废除这个规定之后，其他种类数量就会恢复
削弱：B选项表明狩猎者已经很久没有在schedule date前就狩猎到达5%了，说明hunters狩猎的snow geese需求量已经不大了，所以废除这个规定，也不会使得snow geese数量减少。
我认为B选项的意思是说，在法规起作用使得狩猎季提前结束已经过去很多年了。有点绕哈，it has been many years since we met last time不就是说在我们上次见面之后已经很多年了。句式差不多意思也差不多，楼主多多体会一下哈，还可以再多多探讨。

Irene1221

非常感谢，终于绕明白了。还是我自己对问题的理解有些偏差。