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.

我选B。

题中the hunting season ends if and when hunting has reduced the population by five percent, according to official estimates，并没有说这个end是由于restriction的原因。而结论说不要restriction就能使另一个物种恢复，显然这中间存在一个gap。weeken的时候就可以找这个gapweeken。

看选项，A说restriction的建立时间，无关项。

C说hunter每年捕的鹅数量在增多，无关。

D鹅的数量增多了于是就怎样怎样。我看不出来和题目有什么关系哈……

E说鹅没有天敌。不管有没有天敌，人都是要捕杀它们的。排除。

下面分析B。阅读有点绕，但它的意思是说这个restriction已经被废除有几年了。很好的找到了题中的gap。已经被废除了，然而仍然是到5%的时候就end，所以, dropping this restriction would allow the other species to recover被weeken。

个人见解……不知道说清楚了没有……