5. 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. 答案是 D 但我不太了解 题目是说 tiger sharks 通常以 small sharks 为食 如果市长把海滩附近的 tiger sharks 杀光 那以正常情况而言 small sharks 会增加 这对答案 D 中的 fisheries 应该是有利的 为什麽反而是使市长的政策不能执行的原因? 感谢!! --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 118.166.220.223