单选题 3. The use of nets at beach resorts to protect swimming areas from sharks has been criticized by environmentalists because the nets needlessly kill thousands of marine animals annually. However, environmentalists have recently discovered that an electrified cable buried beneath the periphery of swimming areas causes sharks to swim away while harming neither humans nor marine life. Hence, by installing such cables, resort communities will be able to maintain tourism while satisfying environmentalists' concerns.
Which of the following, if true, most seriously weakens the argument? ______

A、 Many seaside resort communities where sharks have never been sighted nonetheless paid to install buried electrified cables.
B、 Tourism at resorts where sharks have been sighted has suffered only slightly despite the fact that many people claim to fear sharks.
C、 Because they have a strong fear of sharks, many tourists prefer to swim at beaches that are known to be well protected from sharks.
D、 The buried electrified cable is not the only innovation approved by environmentalists that is known to be successful in repelling sharks without harming them
E、 The marine mammals that are a major tourist attraction at many resorts do not enter areas around which there are buried electrified cables.

【正确答案】 E

【答案解析】 E：该选项说明，因为装了电缆，反而会使得吸引游客的海洋动物也远离景区，这对旅游业来说是一种破坏，属于“直接削弱结论”，正确、
A：原文讨论的是用电缆驱赶鲨鱼是否会影响景区的旅游业，与那些本来就没有鲨鱼出没的景区无关，故不选。
B：文章最终讨论的是安装电缆对于景区旅游业的影响，和鲨鱼是否影响旅游业无关，故不选。
C：安装电缆是防范鲨鱼的一种方式，而游客更喜欢在这些景区旅行，这是促进旅游业，加强原文，故不选。
D：电缆不是唯一的让环境保护主义者认可的驱赶鲨鱼的方式，这至少证明电缆可以保证旅游业又能使得环境保护主义者安心，虽然利用其他方式也能达到这一目的，但是电缆达到这一目的的可能性并没有被削弱，故不选。