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 farms 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.
答案给的是B,可是我怎么也不明白,我自己觉得是E。
为什么别的作物用的农药的价格会有关系呢?问得是关于种cotton的farmers啊。 E, 如果大多数report用新种子的farmer原来的用农药量很大,(假设100)而现在(假设40)和一般的farmer差不多(假设50),那么因为比较本身的不对等性带来了问题,不能说明这种新种子不好。反过来则说明两边结果可比,那就说明新种子确实不怎么经济。
为什么选B呢? 谢谢NN们指导
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