GWD的完成题，怎么看呢？

Xiaotongdi

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?

1. Whether farmers who tried the modified cotton seed had ever tried growing other crops from genetically modified seed
   
2. Whether the insecticides typically used on ordinary cotton tend to be more expensive than insecticides typically used on other crops
   
3. Whether for most farmers who grow cotton it is their primary crop
   
4. Whether the farmers who have tried the modified seed planted as many acres of cotton, on average, as farmers using the ordinary seed did
   
5. Whether most of the farmers who tried the modified seed did so because they had previously had to use exceptionally large quantities of insecticide
   这题的答案是D，但是我选了B，我觉得既然和经济有关，那应该涉及到成本啊，那么杀虫剂的成本不是应该很重要么？
   

clumsy123

貌似正确答案是B耶。。。。

Xiaotongdi

呃……我晕！看来要变成……求正确答案！

lonelyorchid

据说是prep的题 B

ruirui_hsu

我觉得B 那个other crops是无关啊。
题目本身说是cotton modified前后进行比较，跟其他crop没关系吧

weijiejing

B是无关的 和other crops没有关系
D是正确答案 如果用了新棉花的人没亩种的棉花比没用新棉花的人种的少或者多,那就无法根据他们用杀虫剂的量来判断新棉花在经济上的好坏了

lala974

i vote for D