标题: GWD7-11 麻烦大家帮我看下 有点转不过来 [打印本页] 作者: monica315 时间: 2011-5-2 01:22 标题: GWD7-11 麻烦大家帮我看下 有点转不过来 In 1992 outlaw fishing boats began illegally harvesting lobsters from the territorial waters of the country of Belukia. Soon after, the annual tonnage of lobster legally harvested in Belukian waters began declining; in 1996, despite there being no reduction in the level of legal lobster fishing activity, the local catch was 9,000 tons below pre-1992 levels. It is therefore highly likely that the outlaw fishing boats harvested about 9,000 tons of lobster illegally that year. Which of the following is an assumption on which the argument depends? A.The illegal lobster harvesting was not so extensive that the population of catchable lobsters in Belukia’s territorial waters had sharply declined by 1996 B.The average annual lobster catch, in tons, of an outlaw fishing boat is has increased steadily since 1992. C.Outlaw fishing boats do not, as a group, harvest more lobsters than do licensed lobster-fishing boats. D.The annual legal lobster harvest in Belukia in 1996 was not significantly less than 9,000 tons. E.A significant proportion of Belukia’s operators of licensed lobster-fishing boats were out of business between 1992 and 1996 麻烦大家帮我看看、答案是A、我也不是完全想不明白,就是好像明白了一秒马上就又糊涂了。我不是太理解结论是怎么来的。作者: sdcar2010 时间: 2011-5-2 09:40
Necessary assumption. Use negation.
If you negate A, you have "The illegal lobster harvesting was so extensive that the population of catchable lobsters in Belukia’s territorial waters had sharply declined by 1996." If this is true, then the total avaialbe lobsters for both legal and illegal catchers are declined sharply. Therefore the 9000 ton difference between 1996 and 1992 are less likely to be caused by the illegal harvest. The conclusion does not hold. So A is the correct answer.作者: clumsy123 时间: 2011-5-2 16:32
sd大侠，您真是头像控啊！