天山-3-3Q3:
Scientists have made genetic modifications to cotton to increase its resistance to insect pests. According to farmers’ reports, 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 .
I have read a lot discussion about this question.but i am still not sure which answer is the best
answer,is it possible that this 问 题 是 考 样 本 是 否 有 代 表 性 ， 因 此 答 案 D回 答 结 论 “According to farmers’ reports, 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.’ 是 否 正 确
so i thank that D maybe the right answer?
hope NN explain it to me?
thank a lot?
作者: wzguai 时间: 2005-1-14 07:31
同意考 样 本 是 否 有 代 表 性的说法,但支持E.
D: the amount of insecticide needed PER ACRE 已经说明D不对
E 中说明参加者不具代表性, 所以证据错,结论也就错了.
--personal opinion
作者: cicilla 时间: 2005-1-14 11:58
B吧？无论评价是什么，至少要说明是否”benefit most cotton farmers economically"这个结论吧？
说来说去，农民最关心的是经济效应。
作者: WalkByFaith 时间: 2005-7-4 00:07
up D!
作者: wzparete 时间: 2006-2-22 01:24
E中的other crops没有问题，如果是other type crops的话就不包括改良的cotton，支持B。
作者: wzparete 时间: 2006-2-22 01:36
最后一句话：switching to the modified seed would be unlikely to benefit most cotton farmers economically. 如果题目最后一句改为benefit the farmer who use the modified seed,而不是most cotton farmers E就对。
还是支持B。
作者: yukovan 时间: 2006-2-23 10:47
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.
应该做纵向比较，而非横向比较；如果要做横向比较，那需要一个premise：被比较的farmer除了选的种子不同，其他都一样。E refuted this premise, that's why the best answer.
In a controlled experiment, you can only change one variable at one time.
Otherwise, you cannot tell which variable cause the result.
作者: wycg 时间: 2006-2-23 12:39
B是无关项, E对.
作者: vanessav 时间: 2006-6-29 01:50
除非有人做到
Gmat prep里面有这个题目，要不也难以下定论啊
作者: Jerryxe 时间: 2010-9-3 21:10
前面讨论太多了。我来说说。
1.E选项说，是否这些农民选择用改良棉花，因为他们之前要用exceptionally large的杀虫剂。要理解这个exceptionally large。
比如说有A和B两个农民，以前都是种普通棉花，A因为情况特殊（比如田的位置不好），必须用exceptionally large量的杀虫剂，所以A可能得用200磅杀虫剂，B只需要100磅。
而A改用改良棉花后，发现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，即在改良后，用的杀虫剂，比那些用传统棉花的人没少多少。这里就是A用改良棉花了，B没用，A发现没比B少多少，A还得用90磅，B照样用100磅。
但是因为A以前要用200磅，现在只用90磅，所以A赚到了。
结论，选E。
| 欢迎光临 ChaseDream (https://forum.chasedream.com/) | Powered by Discuz! X3.3 |