GWD一道逻辑~

annieview

11. GWD17-Q11:
Some species of Arctic birds arethreatened by recent sharp increases in the population of snow geese, whichbreed in the Arctic
and are displacing birds of less vigorous species. Although snow geese are a popular quarry for hunters in the southernregions where they winter, the hunting season ends if and when hunting hasreduced the population by five percent, according to official estimates. Clearly, dropping this restriction would allow the other species torecover.
Which of the following, if true, mostseriously undermines the argument?

A.     Hunting limits for snow geese were imposed many years ago in response toa sharp decline in the population of snow geese.
B.     It has been many years since the restriction led to the hunting seasonfor snow geese being closed earlier than the scheduled date.
C.     The number of snow geese taken by hunters each year has grown every yearfor several years.
D.     As their population has increased, snow geese have recolonized winteringgrounds that they had not used for several seasons.
E.       In the snow goose’s winter habitats,the goose faces no significant natural predation.
it has been many years since + 过去式，表示这个过去的动作没有发生很多年了。B说即使在有restriction的时候，人们也在限制期前就停止打猎了
scheduled date是restriction的限制期吧？ 那如果是这样的话，B选项的意思应该是  "hunting season 在限制期前结束"已经很久没发生了把？就不能选了啊？
求解~

annieview

懂了1~thank u~

TopTerminator

The scheduled date for the hunting season to end is on September 30. But if 5% of the geese population has been reduced before September 30 in a given year, the hunting season will end on a date before reaching the scheduled date -- September 30.

annieview

B. It has been many years since the restriction led to the hunting season for snow geese being close ...
TopTerminator 发表于 2012-4-16 20:47

well,thanks!~i dont get the part"the restriction led to the hunting season for snow geese being closed earlier than the scheduled date".
what does scheduled date mean/?

TopTerminator

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

In other words, what B says is that the 5% reduction in geese population due to hunting has never been reached for many years. Since B means hunters could not kill more than 5% of snow geese in a hunting season for many years, more than 5% reduction in geese population is unlikely to be reached even if such restriction is removed. In terms of grammar, It has been many years since (an event happened at a time in the past), simply means the time that event did happen was a long time ago.

Thus, answer B 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.  B weakens the argument.

If the hunting season was not closed early last year, that means the loss of the geese was below 5% of their population due to hunting.

Then if you remove the restiction of "only 5% of geese can be shot down each year," what kind of effect would you have on the geese population?

Nothing! Because the same hunters would show up and shot down the same number of geese - less than 5% of the total, just like what happened last year.