请教一道越想越晕的··GWD。。。

xyqirene

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?

A.The number of school nurses employed by Renston’s elementary schools has not decreased over the past ten years.

B.Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.

C.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.

D.The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.

E.Children attending elementary school do not make up a larger proportion of Renston’s population now than they did ten years ago.


我按排除和技巧选出来了答案C
但是还是不能理解，C答案取非了以后不是加强了摸？

aomeisoft7

现在过敏的学生多了，推出>> 现在学生总数变多 or 现在的学生比以前更敏感

C.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.
送医院的标准不同。比如10年前长10个痘痘才送医院，现在长5个痘痘就送医院。标准不同了，现在送医院的人就多了。
取非检验，如果标准不同，那么推论就不止上面2个原因，还要加送医院标准不一样这个原因，削弱结论，所以必为假设