[求助] 模考中遇到一条鲨鱼

Tiger sharks are common in the water 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

觉得挺奇怪的！既然tiger sharks 以捕食small sharks为生，而 small sharks 又对当地渔业很重要，
            那么杀了tiger sharks应该对当地经济起正面作用啊？万般无奈下，我选了E。请指点迷津，
            谢谢！！

把tiger shark杀了,小鲨鱼就会增多,小鲨鱼增多,fish就会减少,对渔业起负面作用

lz没有看懂选项

咱们分析D的语法：    The small sharks on which feed on fish that are commercially important to the island’s fisheries.  the small sharks是主语，feed是谓语，fish是宾语。 on which tiger sharks prey 是修饰small sharks的定语从句。 后面的那个that are commercially.... 是修饰fish的定语从句。 简言之，大鲨鱼吃小鲨鱼，小鲨鱼吃小鱼鱼，小鱼鱼是带来money的鱼。

豁然开朗！其实是个语法题~~~!!多谢楼上两位指点。

不知道当时自己怎么就没看明白，唉！