OG13 CR68 小白跪求大神帮忙T T

zjhuruoxi567

Scientists have modified feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modified corn last season applied less insecticide to their corn fields and still got yields comparable to those they would have gotten with ordinary corn. Ordinary corn seed, however, costs less, and what these farmers saved on insecticide rarely exceeded their extra costs for seed. Therefore, for most feed-corn farmers, switching to genetically modified seed would be unlikely to increase profits.
Which of the following would it be most useful to know in order to evaluate the argument?
(A) Whether there are insect pests that sometimes reduce feed-corn yields, but against which commonly used insecticides and the genetic modification are equally ineffective
(B) Whether the price that farmers receive for feed corn has remained steady over the past few years
(C) Whether the insecticides typically used on feed corn tend to be more expensive than insecticides typically used on other crops
(D) Whether most of the farmers who tried the genetically modified corn last season applied more insecticide than was actually necessary
(E) Whether, for most farmers who plant feed corn, it is their most profitable crop

A怎么都想不通啊…比如说转基因的可以对抗这种害虫而杀虫剂不能，那用转基因的不就可以提高产量，这样不就是能提高利润吗？怎么理解OG的解释里说有无效和是否能增加利润无关呢…谢谢大家花时间解答！❤️

alzn2765

你没看懂A选项说什么，仔细看一次跟你上面说的一样吗？

zjhuruoxi567

alzn2765 发表于 2015-5-25 18:36
你没看懂A选项说什么，仔细看一次跟你上面说的一样吗？

啊懂了！A的意思的重点在是否存在这样一种害虫是吧？重点在前半句话而不是后半句话。所以是否存在这样一种害虫对于利润来说是无关的，因为假设了转基因和杀虫剂对于这种害虫是同等效果

zjhuruoxi567

alzn2765 发表于 2015-5-25 18:36
你没看懂A选项说什么，仔细看一次跟你上面说的一样吗？

那如果这个选项重点变一下，变成whether 转基因和杀虫剂 are equally ineffective to some insects that can reduce the yield of the corn是不是就可以用来evaluate了？