天山-3-3

Q3:

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 think B is irrelevant. E is better, although the suggested answer is B.

E不是答案，原文中说的很清楚，杀虫剂只是轻微的减少了。所以如果原来的杀虫剂的量特别大的话，改良的种子还是需要大量的杀虫剂，从而在杀虫剂的使用成本上没有改变，加上modified seed costs more than ordinary seed without producing yields of higher market value，无论E肯定与否，都不能影响原文的结论。

B说的以前的杀虫剂的价格是不是比其它的都贵，如果是的话，那么在使用杀虫剂的成本上，改良的种子降低了，从而影响原文的结论。vice vesa.

答案为D;

本题的考点比较细, 虽然文中给出两者比较的差异和相似之处, 但答案中的信息确实不明显;

看看D, who所引导的现在完成时态决定了答案, 为何? 很明显, 那些曾经种过基因种子的农民自然知道是否有利,至于在哪些方面有利,答案没有提及, 也不是我想关心的, 但农民种东西总不会喜欢亏本吧? 根据那些种过基因种子的农民前后变化的差异和相似之处,可以起到对文中推论加强或者削弱的目的;

I agree with JOE on this quetion

The conclusion of the argument is that switching to the modified seed would be unlikely to benefit most cotton farmers economically.

The paragraph is related to cotton farmers, therefore, the choice should cover the topic within cotton. However, Choice B unfortunately makes a contrast between ordinary cotton and other crops.

E的答案明显无法构成削弱或者加强: E中说是因为从前(与现在形成对比)杀虫剂太多(估计比土地都多的程度了,呵呵)才采用基因种子的, 而现在呢? 文中给出了: 其实用量跟基因种子差不多(注意文中的表达: slightly lower); 那么如何判断现在使用两种种子带来的经济效益呢? 至少从E是推论不出来的;

注意原文的推倒：因为新种子的成本比原来的高，而且又没有产生更高的市场价值——>用新种子不能给棉农带来经济利益。

这是一个呆评价的推理，也就是我们通常所说的演绎推理，前提推结论之间不是must be的关系。因为经济利益除了种子成本与市场价值以外还有其它的因素，比如B中所说的杀虫剂的成本就是其中一个因素。杀虫剂的量原文已经比较过了，所以杀虫剂的价格是一个考量。因此B是答案。其它均为无关选项。

你所说的原文推倒确实是正确的,但B的回答中,只有no才可以对原文起到一个加强的效果, 如果回答yes呢? 根本就推不出对原文的结论是削弱的: 看看这种回答之后的双方比较- 基因种子(文中的两个不利条件) : 普通种子(回答之后的不利条件);

借用一句广告语来回答本题的答案: 谁用谁知道................

同意GERRY., 答案是E.

B. 用在棉花上的杀虫药比用在别的农作物上的杀虫药贵， （自己和别人比较）

E. 自己目前用在棉花上的杀虫药的量比自己以前用在棉花上的杀虫药量少， （自己和自己比较）

欧也是想找个杀虫药便宜的，省点钱么。

原文，切换到21世纪的今天，俩农民兄弟种棉花，农民甲种了新品棉，农民乙种常规棉。

二人每亩地用等剂量的打虫药，如10升ddv。

农民甲以前也是种常规棉的，和农民乙一样。

现在农民甲发现每亩地多花100块大洋种的新品棉比以前少用了许多打虫药ddv，

假设 ddv 贵得超过了100块大洋， 那么农民甲还是省了不少人民币。  

That explains answer E.

对于 Choice B, 农民甲发现喷在棉花上的 ddv 的量和 喷在小麦上的 ddv 的量差不多，

这如何推导出新品棉多花钱还是少花钱呢？