求指导一道CR。。。

尹潇尘

prep模考的时候做到的，可是百思不得其解。。。求NN指导。。。

Tiger sharks are common in the waters surrounding Tenare Island.Usually tiger sharks feed on smaller sharks, but sometimes they have attacked tourists swimming and surfing at Tenare's beaches.This has hurt Tenare's tourism industry, which is second only to its fishing industry in annual revenues.In order to help the economy, therefore, the mayor of the island has proposed an ongoing program to kill any tiger sharks within a mile of the beaches.

Which of the following, if true, most strongly calls into question the likelihood that implementation of the mayor's proposal will have the desired consequence?

(A) Even if not all the tiger sharks that come close to the beaches are killed, the existence of the program would reassure tourists.

(B) Business owners who depend on tourism are willing to pay most of the cost of implementing the program.

(C) Tourists come to Tenare Island for its beaches, even though the island features a number of other tourist attractions.

(D) The small sharks on which tiger sharks prey feed on fish that are commercially important to the island's fisheries.

(E) Not all tourists who come to Tenare Island enjoy swimming or surfing.

求指导啊求指导= =。。

gutter1900

个人认为是A, 如果不能确定所有虎鲨都被杀死，原条件就不成立，多旅游业的影响就仍然催在。不明显，但又weaken的作用。不确定，同求高手解答。

尹潇尘

个人认为是A, 如果不能确定所有虎鲨都被杀死，原条件就不成立，多旅游业的影响就仍然催在。不明显，但又weaken的作用。不确定，同求高手解答。

-- by 会员 gutter1900 (2011/12/9 20:19:26)

其实我也选的A。。。可是正确答案是D。。。。所以我百思不得其解啊。。。

HarrisZheng

A 是支持 即便不杀光虎鲨 游客也会感觉放心
D 说虎鲨吃小鲨鱼 小鲨鱼吃渔业中有重要经济价值的鱼 也就是说虎鲨是小鱼天敌的天敌 如果把虎鲨杀了 小鲨鱼就会增加 小鱼就会减少 进而影响当地渔业

sdcar2010

D is the answer.

The tiger shark eats the small sharks. The small sharks eat fish. Fishermen catch fish to sell.

Killing tiger shark would increase the number of the small shark, which would eat more fish. Fisherman would have fewer fish to sell.

gutter1900

...没仔细看题  原来渔业是当地第一产业啊  所以影响渔业肯定不行的  感谢高手指点

戴小真

选D吧

尹潇尘

终于明白了。。。感谢各位大神。。。