求解一道CR题

eliasfan

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.

eliasfan

这题看了半天都不知道为什么会选B
求NN们指点

夜幕如斯

额，我觉得b是加强啊，因为限制使得打猎季节在达到一定数量的时候（减少了5%）就提前结束了，那么没有这个限制不就会打猎的更多，然后减少geese的数量吗？

求解~

eliasfan

有同感，所有纠结

sdcar2010

The answer is B, which claims that the restriction set has no effect on the highest number of geese killed in a hunting season.  Therefore, removing the restiction would not lead to more killings of the geese and better chances for the other species to recover. Thus, B weakens the argument.

In other words, what B says is that the 5% reduction in geese population due to hunting has never been reached for many years. Therefore, more than 5% reduction in geese population is unlikely to be reached even if such restriction is removed.

eliasfan

If the aim of  the 5% reduction in geese population  has never been reached for many years, why  does the huntering  close earlier than the scheduled date?
As we know  ,the hunting season ends if and when hunting has reduced the population by five percent, according to official estimates
From B we can see if we remove the restriction, we can hunter more snow geese, and  recover the Arctic birds
So B strongthen the argument!

sdcar2010

LS, you did not understand the meaning of answer choice B.

It has been many years since I visited Beijing. Did I visit Beijing recently? No.

B.It has been many years since the restriction led to the hunting season for snow geese being closed earlier than the scheduled date.

Was the hunting season closed earlier than the scheduled date recently? No.