作者：英吉
Scientists have made genetic modifications to cotton to increase its resistance to insect pests. According to farmers’ report, the amount of insecticide needed per acre to control insect pests was only slightly lower for those who tried the modified seed than for those who did not. Therefore, since the modified seed costs more than ordinary seed without producing yields of higher market value, switching to the modified seed would be unlikely to benefit most cotton farmers economically.
Which of the following would it be most useful to know in order to evaluate the argument?
A. Whether farmers who tried the modified cotton seed had ever tried growing other crops from genetically modified seed
B. Whether the insecticides typically used on ordinary cotton tend to be more expensive than insecticides typically used on other crops
C. Whether for most farmers who grow cotton it is their primary crop
D. Whether the farmers who have tried the modified seed planted as many acres of cotton, on average, as farmers using the ordinary seed did
E, Whether most of the farmers who tried the modified seed did so because they had previously had to use exceptionally large quantities of insecticide
题目分析：就是原文认为用新的这种种子好像不省钱，五个选项在评论这个话题，我们看看哪个跑题，A说用这种种子的农夫曾经尝试种其他农作物，种其他农作物，跑题了，杀。B说用于普通棉花上的杀虫剂比用于其他农作物的杀虫剂要贵，说的是杀虫剂的价格问题，跑题了，杀。C说农夫是否把棉花当做主要农作物，原文也没说这个，跑题，杀。D说种这种新种子的农夫会像用其它普通种子的的农夫一样种相同面积的棉花，说的是我种的面积是否和原来一样，至少谈的是一个事，没跑题，留着。E说用这种新种子的农夫之所以用这种新种子是因为他们以前不得不用大量的杀虫剂，没说，跑题，杀。
