A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous. B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use. C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population. D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch. E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting. 首先,文章已经说了,人类每年捕鱼的数量没有大幅增加,所以A和B都排除,因为A说人类捕鱼范围扩大而B说的是人类捕鱼效率提高,C是人们捕捉鳄鱼的原因,无关也排除,E说邻国怎样,也排除,就只剩D了 也可以这么想,为什么鳄鱼少了,它吃的鱼不但没多,反而也少了呢?4个选项里面,只有D说了鳄鱼在这种鱼的繁衍中起的作用,就是鳄鱼挖洞,鱼就在那些洞里孵化,所以鳄鱼少了,没有人挖洞了,那些鱼也就少了。 |