OG13 68题

ljwqlcl881703

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
无法理解答案为啥选D  看了好多前辈的帖子 说什么根据选项D 降低杀虫剂用量可以提高产量 原文中没题这个问题  选项难道在说这个问题 ？
谢谢！

ljwqlcl881703

看D选项。若回答yes，即农药用多了，那么减少农药使用量之后，农药save增加，超过extra cost的话，可得出结论：用转基因种子能获利。 若回答no，农药用量合适，那么农药save确实小于extra cost，则转基因种子不能增加利润。
这是其中一为前辈给出的解释   你农药使用量少了 SAVE=数量X单位SAVE价格   单位SAVE价格不变  数量减少  SAVE 如何增加 真心觉得神逻辑 小弟逻辑太菜  无法理解  来个NN人帮忙

ljwqlcl881703

可以来个人帮忙么  真心不明白

ljwqlcl881703

来个银 求拯救！

llmmlemon

题干中是将节省下的农药cost与买基因改良种子的COST相比（前者比后者小），结论该种子不能提高利润。那么为了评估该结论，正确选项应该是能影响到至少这两种COST之一的。D选项与农药COST有关。

xiqiong

楼上正解~ 其实你就这么看~
为什么说改基因的没有用呢~就是没有节约钱~  
我们怎么来评估这一说法呢~
D选项说的就是，如果说，你本来可以节约的，你自己多花了（多喷了农药），那么，下一年，你少喷之后，其实是可以节约钱的。
不用算算术算那么清，只要抓住是否省钱这块来看，影响COST就是正确选项。

ljwqlcl881703

llmmlemon 发表于 2013-8-12 09:19
题干中是将节省下的农药cost与买基因改良种子的COST相比（前者比后者小），结论该种子不能提高利润。那么为 ...

谢谢哈 明白了

ljwqlcl881703

xiqiong 发表于 2013-8-12 10:03
楼上正解~ 其实你就这么看~
为什么说改基因的没有用呢~就是没有节约钱~  
我们怎么来评估这一说法呢~

恩恩 谢谢啦~~~