标题: 求助！07Prep one [打印本页] 作者: shunliqumeiguo 时间: 2010-10-29 20:19 标题: 求助！07Prep one 5. (24371-!-item-!-188;#058&000859)
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.
答案D,为什么呢？说不过去啊作者: eshopaholic 时间: 2010-10-29 20:27
it's a food chain
small fish --- small shark --- tiger shark
the decrease of the tiger shark population will lead to the increase of the small shark population, thus less small fish for fishing industry作者: gaor 时间: 2010-10-30 01:55
D说明，捕杀 tiger shark 会影响 渔业，从而影响经济作者: 三零年代 时间: 2010-10-30 09:44
第一遍下来，只有D才能call into question啊。 其他完全不沾边的。
(A) Even if not all the tiger sharks that come close to the beaches are killed, the existence of the program would reassure tourists. 不会weaken结论。是weaken premise. (B) Business owners who depend on tourism are willing to pay most of the cost of implementing the program. 无关，一点没有weaken的味道 (C) Tourists come to Tenare Island for its beaches, even though the island features a number of other tourist attractions. 同A (D) The small sharks on which tiger sharks prey feed on fish that are commercially important to the island's fisheries. 正解 (E) Not all tourists who come to Tenare Island enjoy swimming or surfing. 无关。 做weaken题目，首先要分清，argument, premise,evidence和concolusion. 题目问weaken conclusion，那么必定是在premise ,evidence的基础上weaken.