A6.Parland's alligator population has been declining in recent years, primarily because ofhunting. Alligators prey heavily on a species of freshwater fish that is highlyvalued as food by Parlanders, who had hoped that the decline in the alligator population wouldlead to an increase in the numbers of these fish available for humanconsumption. Yet the population of this fish species has also declined, even thoughthe annual number caught for human consumption has not increased.
Which of the following, if true, most helps to explainthe decline in the population of the fish species?
(A) Thedecline in the alligator population has meant that fishers can work in some oarts of lakesand rivers that were formerly too dangerous.
(B) Overthe last few years,Parland's commercial fishing enterprises have increased the number offishing boats they use.
(c) The main predator of these fish is another species of fishon which alligators also prey.
(D) Many Parlanders who hunt alligators do so because of the high marketprice ofalligator skins, notbecause of the threat alligators pose to the fish population.
(E) In several neighboring countries through whichParland's rivers also flow, alligators are at risk of extinction as a result ofextensive hunting.
c是正确选项，但是我主要是纠结在后面那句话，alligator 也吃那个fish的天敌，天敌减少了，fish不是应该增多么？？想不通呀！！求高人指点
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发表于 2012-12-5 12:22:53
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