Insect infestations in certain cotton-growing regions of the world have caused dramatic increase in the price of cotton on the world market. By contrast, the price of soybeans has long remained stable. Knowing that cotton plants mature quickly, many soybean growers in Ortovia plan to cease growing soybeans and being raising cotton instead, thereby taking advantage of the high price of cotton to increase their income significantly, at least over the next several years. Which of the following, if true, most seriously weakens the plan’s chances for success? A. The cost of raising soybeans has increased significantly over the past several year and is expected to continue to climb. B. Tests of a newly developed, inexpensive pesticide have shown it to be both environmentally safe and effective against the insects that have infested cotton crops. C. In the past several years, there has been no sharp increase in the demand for cotton and for goods made out of cotton. D. Few consumers would be willing to pay significantly higher prices for cotton goods than they are now paying. E. The species of insect that has infested cotton plants has never been known to attack soybean plants. 答案选B,但是讲杀虫剂跟要削弱的内容感觉无关啊。我选了C,需求没有增加,如果供应增加,价格还是会下降的,正好削弱啊。NN看看我的思维问题在哪? -- by 会员 gmatbiguo (2011/5/6 20:24:52)
这个题挺经典的..涉及到一个主论据的问题..是这样的.. insect泛滥 导出 cotton的价格up 导出 种植cotton就会income up.. 这个显然是一个多论据架构..这个时候要抓主论据..也就是根本性的论据..在本题中根本的论据是昆虫泛滥..因为从这里可以导出其他论据..它是文章逻辑链的起源.. 逻辑题的正解一定要与主论据相关..所以直接朝着与insect有关的选项去就可以.. 再次结合削弱题的本质..就是主论据即使成立了..结论也不一定成立..解释起来就是.. 就算昆虫感染泛滥了..也推不出income up..因为一种杀虫剂有效的遏制了这种虫害...抽象的说就是另外一个信息削弱了论据的力度.. 下面说说为什么C不对..C是一个典型的引入无关时间变量的选项.. in the past several years..而原文给的时间是the next several years.. 这种错误还是蛮典型的..不知楼主明白了不?呵呵~ |