Parland’s alligator population has been declining in recent years, primarily because of hunting. Alligators prey heavily on a species of freshwater fish that is highly valued as food by Parlanders, who had hoped that the decline in the alligator population would lead to an increase in the numbers of these fish available for human consumption. Yet the population of this fish species has also declined, even though the annual number caught for human consumption has not increased. Which of the following, if true, most helps to explain the decline in the population of the fish species?
The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.
Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.
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.
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.
In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.
明白了。正确答案应该是D。因为D说alligator 这种鱼在干燥的季节可以挖洞，洞里面的水足以供alligator的蛋进行孵化，也就是说洞里的蛋将来孵化成alligator，然后又可以吃人们（Parlanders）爱吃的鱼（freshwater fish ），因此说明了freshwater fish为何减少了。而答案B说渔船增加并不能说任何问题，你能说钓的鱼增加了吗？不能，因为题目主干最后一句说的很明白。不知解释的是否正确和明白？
以下是引用sv2000在2005-11-12 10:37:00的发言： 明白了。正确答案应该是D。因为D说alligator 这种鱼在干燥的季节可以挖洞，洞里面的水足以供alligator的蛋进行孵化，也就是说洞里的蛋将来孵化成alligator，然后又可以吃人们（Parlanders）爱吃的鱼（freshwater fish ），因此说明了freshwater fish为何减少了。而答案B说渔船增加并不能说任何问题，你能说钓的鱼增加了吗？不能，因为题目主干最后一句说的很明白。不知解释的是否正确和明白？
答案是D，不过不是很同意你的解释，首先alligator是一种鳄鱼，在干燥的季节可以挖洞，洞里面的水足以供freshwater fish 的蛋进行孵化，alligator的数量下降，他们挖的洞的数量也下降，可供freshwater fish 的蛋孵化的地方也就少了，所以freshwater fish 的数量就下降了。
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发表于 2005-11-11 13:59:00
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