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地板
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发表于 2016-3-20 19:29:02
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86. 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
B ×
结构:BG:转基因的作物不容易受害虫的影响从而可能会提高产量,但是农民发现这个产量和用普通种子的产量没什么区别, 转基因品种的种子虽然可以节省点买杀虫剂的钱,但是省的钱都不够来买种子。C:所以用转基因种子并不会提高收益
概括下: 普通种子:种子价格便宜,需要的杀虫剂多;
转基因:种子价格贵,需要的杀虫剂少
【评估题】 “To answer a question such as this , one should look for information that would strengthen or weaken the argument.”-------OG
收益与哪些要素有关:售价(由市场决定,农民伯伯控制不了),产量(产量题目已知用两种种子一样),成本(种子价格,杀虫剂)----评估的要素:成本
A. 害虫主要是影响作物产量,已知条件中已经确认产量一样,无效信息;
B. 售价因素,可是这个不能用来评估,因为价格的变动对两种不同种子产生的结果是一样的,市场价高的不管是便宜的种子还是贵的种子一样赚钱;而且这个要素不被农民所控;
C:谈及成本要素,但是说的是在不同的作物上使用的效果,不能说明与种子价格的关系
E:与评估方向无关
KEY:D 谈及评估的要素---杀虫剂的使用;可能是因为农民伯伯多用了本来不需要使用的杀虫剂,从而使成本增加,而这个成本是可控的;
【评估题的感悟】
1.评估题不同于假设题,假设题是一个argument形成的基础,而评估题是评估argument提出的方案的可行性或者言论的正确性; 比如这题中B如果作为假设题,结论建立在什么假设之上—几年的市场价格都没变---那么可能正确
2.评估题的关键是找到评估的方向,找到事件发生变化影响因素是什么,这个要素可控吗?然后从这个因素去找答案;
3.评估的另一个要素是:站在哪个人的角度在评估?不同的角度评估出的结果不一样
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