xdf蓝皮书29

windows10

29.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 emplyees in major zoos,about 30% 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% but substantially more.

Which of the following,if true,provides the strongest grounds for the experts' conclusion?

A.A zoo employee who develops a serious animal-induced allergy is very likely to switch to some other occupation.

B.A zoo employee is more likely than a person in the general population to keep one or more animal pets at home.

C.The percentage of the general population whose level of explosure to animals matches that of a zoo employee is quite small.

D.Exposure to domestic pets is less likely to cause animal-induced allergy than exposure to many of the animals kept in zoos

E.Zoo employees seldom wear protective gear when they handle animals in their care.

答案是A,我也选对了，但是是因为其他选项根本就不沾边，请教大家为什么A对了。谢谢！

xiaoaojiang

题目说了sample 是30% 而population 是不只30% 所以说A对

bettytons

我是这样理解的，对于无论是在动物园工作的人还是对在其他岗位工作的人来说，如果和动物相处同样多的时间，对动物的过敏程度是相同的，都是人。

在动物园工作的人，正如 A 所讲，如果严重过敏就会转到其他职位去工作，这样其他岗位工作的人对动物过敏的百分比率就会增加，所以要高于30%，就加强了观点

yoyo561116

It can be intepret in the following algrithm:
Since the people with serious animal allergy will not be able to afford the work in zoo, the percentage of the workers with animal allergy will be lower than that of the regular group of people. Consquently the percentage of general population with allergy-induced allergy should be higher than that of zoo workers.

windows10

嗯，知道了，谢谢!

min356478

刚好做到这个题目。

是不是应该说：

动物园的人过敏马上就换工作。

有可能动物园的人是100%过敏，只是因为过敏了马上换工作，新来的人还没有过敏，所以看起来好像只有30%。实际上那些新来的人过不了多久也会过敏。

quellekind

我觉得skyzhang想复杂了。没有理由假设动物园的人过敏率是100%。而且也不需要这样假设。只是因为动物园的工作人员过敏会换工作，所以among the members of the population who have a similarily large amount of time in close contact with animals,过敏率会高过30%。