GMAT-26-22请教求解思路

sv2000

People who have spent a lot of time in contact with animals often develop animal-induced allergies, some of them quite serious. In a survey of current employees in major zoos, about 30 percent had animal-induced allergies. Based on this sample, experts conclude that among members of the general population who have spent a similarly large amount of time in close contact with animals, the percentage with animal-induced allergies is not 30 percent but substantially more. Which of the following, if true, provides the strongest grounds for the experts’ conclusion?

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yangsh

不懂，牛牛帮忙。觉得A也不通

啊？

deanjiang

UP A

文中：

zoo 30％，结论普通人更高。

A说明了调查的时候30%的数字偏低，因为有些已经被感染的人调走了。

sv2000

谢谢3楼解释。

mimixiaxia

up