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标题: 请大牛指点 GWD 31-6-21 [打印本页]

作者: soniashi 时间: 2007-4-9 20:51
标题: 请大牛指点 GWD 31-6-21

为什么就不是B呢？

不是比较费用的问题吗？

而且谈的是平均费用阿，搞不明白和总种植面积有什么必然联系的啊？

谢谢指点阿！

Q21:

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?

Whether farmers who tried the modified cotton seed had ever tried growing other crops from genetically modified seed
Whether the insecticides typically used on ordinary cotton tend to be more expensive than insecticides typically used on other crops
Whether for most farmers who grow cotton it is their primary crop
Whether the farmers who have tried the modified seed planted as many acres of cotton, on average, as farmers using the ordinary seed did
Whether most of the farmers who tried the modified seed did so because they had previously had to use exceptionally large quantities of insecticide

作者: yejinleaf 时间: 2007-4-9 23:13

B 提到other crops,应无关；

个人认为因该是D

考类似经济学里的固定成本与变动成本的问题：

基因改造成本为一次投入固定成本；

农药每亩节约成本为变动成本，亩数越大，节约越多；

sub conclusion，随着种植面积增加，农药节约成本会在某一点超越基因改造成本。

main conclusion,种植面积是衡量是否合算的关键因素。

作者: soniashi 时间: 2007-4-10 09:48

谢谢了

我是把other当作了非基因变异作物了

看来我还是做题太主观了。

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