感觉这题B也是在排除他因呀，为啥选C不选B呢？

frankzhiwei

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.

答案C，why not B？ 谢谢~

shencangbulu

B是无关选项吧.
这题我觉得不是排除他因.而是找出隐含假设.十年前的现象和十年后的现象做比较,有个十年标志会比较靠谱.只有在报送标准一样的前提下,更高数量的案例才能说明孩子是更容易过敏或更多地接触化学物质了.

换成中文你体会一下,不难明白的.

frankzhiwei

感谢，十分清楚！

sunshengkun666

b无关了....