gwd-7-5

jonathan1987

以下是引用sendme在2004-9-28 6:34:00的发言：

Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children.  Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years.  Therefore, either Renston’s schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago.

Which of the following is an assumption on which the argument depends?

1. The number of school nurses employed by Renston’s elementary schools has not decreased over the past ten years.
2. Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.
3. Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago.
4. The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.
5. Children attending elementary school do not make up a larger proportion of Renston’s population now than they did ten years ago.

answer is  C, but i can't figure out the difference between B and C.

pls let me know.

  

这题中,ade 都是无关选项,都可以排除

就是b和c之间的选择, 一开始看b好像是排除他因, 排除是其他物质引起过敏,但是仔细看看题目,上面说Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years.

说明已经是那种物质的过敏, 所以b说关于其他物质的过敏就是无关选项了,

而c说,送去校医那里的病的程度都是差不多的,不会说十年前是病的差不多休克才送去校医那里,而现在是有点症状就送去校医那里,排除了程度上的不同, 是原文的assumption

icindy

我觉得E错误不是像5楼说的：E比较的是学校内部的比例，原文讲的是Elementary school nurses in Renston repots that..., 说的就是在Renston地区的小学，而E的意思是说在Renston地区上小学的人数并不比10年前所占人口的比例大，问题在于E说的是一个比例，而不是一个绝对数，有可能现在总的地区人口数下降，而上小学的人数不变，可所占总人口数的比例还增高了（如E）,

我觉得如果E说的是现在上小学的人数不比10年前上小学的人数多，则也是一个取非削弱。

E的错误是把比例当成了绝对数

但是护士报告的时候说的也是比例上升了。

icindy

两个比例不一样，我搞错了~~确实选C

yangmars

这个解释我看懂了，顶

xieguodong

一点心得：假设是加强的一种，但假设和加强的区别在于假设一定会和前提有关。在结论前面的前提是最重要的前提。在此题中，结论therefore前面的前提和school.nurse有关。BDE都无涉及此概念，无关。A，C涉及了。符合2/5的原则，而A明显不能加强。C即为答案。且可以进行取非削弱的验证，如果取非C，则结论就不成立了。