Sportfishers introduced the Zander, a type of perch, to Britain’s rivers and canals in the 1970s. Because zander eat large numbe

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问题 Sportfishers introduced the Zander, a type of perch, to Britain’s rivers and canals in the 1970s. Because zander eat large numbers of smaller fish, they have had a devastating effect on native fish populations. To protect the native fish, a government program removed a significant proportion of the zander from Britain’s waterways last year. Surprisingly, this year the loss of native fish to zander has been greater than before.
Which of the following, if true, would most help to explain the greater effect of zander on the native fish population?

选项 A、The climate in Britain is very similar to the climate in regions to which zander are native.
B、Most of the zander removed were fully grown, and fully grown zander eat large numbers of smaller zander.
C、Every year a large number of zander are caught by sportfisher in Britain’s waterway.
D、Previous government program designed to remove nonnative species from Britain’s waterways have failed.
E、Zander are just one of several nonnative fish that prey on the other fish found in Britain’s waterway.

答案B

解析 A.The climate in Britain is very similar to the climate in reglons to which zander are native.英国的气候与Zander鱼老家的气候很类似。
解析:该选项只能说明英国适合Zander鱼生存,但无法解释为什么Zander鱼被移走之后,当地鱼群损失反而增大。不选。
B.Most of the zander removed were fully grown,and fully grown zander eat large numbers of smaller zander.大多数被移走的Zander鱼都是成年鱼,并且成年鱼会吃掉大量的小Zander鱼。
解析:在Zander鱼被移走之前,大Zander鱼通过吃掉小Zander鱼来控制Zander鱼的数量。但是大Zander鱼被移走之后,大量的小Zander鱼不受控制,导致来年河道中Zander鱼数量反而增多了,所以因为Zander鱼而损失的当地鱼群会增多。正确。
C.Every year a large number of zander are caught by sportfisher in Britain’s waterway.每年大量的Zander鱼会被英国河道中的钓鱼运动者捕捉。
解析:该选项讲的是每年都会发生的情况,自然无法解释为什么今年当地鱼群损失的数量反而增多。不选。
D.Previous government program designed to remove nonnative species from Britain’s waterways have failed.之前移走英国水道中非当地鱼种的政府项目都失败了。
解析:该选项讲的是之前的项目,而本题讨论的是今年的这个项目,与原文无关,不选。
E.Zander arejust one of several nonnative fish that prey on the other fish found in Britain’s waterway.Zander鱼只是在英国水道中捕食其他鱼群的非当地鱼种中的一种。
解析:注意本文最后一句话the loss of native fish to zander,本文只考虑因为Zander鱼所导致的损失,与其他鱼种无关,不选。
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本试题收录于: GRE VERBAL题库GRE分类
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