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标题: 大全P185的题 [打印本页]

作者: lisiberry 时间: 2017-3-4 23:02
标题: 大全P185的题
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

OA：A

我怎么觉得A就是重复了一下原题呢？

作者: lisiberry 时间: 2017-3-6 04:59
up

作者: 穆汐寒 时间: 2017-3-6 11:22
of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents.
Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
再仔细看看这两句话里的区别
这里实际是做了一个更深的限定
受了伤的80%没系安全带，那还有20%呢，还有没受伤的人就一定系安全带了？

作者: alzn2765 时间: 2017-3-6 13:19

穆汐寒发表于 2017-3-6 11:22
of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at ...

我不知道你是不是真的懂了，至少你的解释并不正确。

作者: alzn2765 时间: 2017-3-6 13:27
首先，这题是assumption题。

作者想证明：
前提:not wearing seat belts--->severely injured
结论：wearing seat belts-->非injured

于是，他用统计证明： of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents.

我们可以很容易的推论出：of the severely injured drivers and front-seat passengers, 20 percent were wearing seat belts at the time of their accidents.
但是要证明wearing seat belts的有效性，我们必须证明：
wearing seat belts的总人数比这个wearing seat belts但是受伤的人要多。否则所有wearing seat belts在事故时全都受伤，那seat belts就没屁用了。

作者: lisiberry 时间: 2017-3-7 04:25

alzn2765 发表于 2017-3-6 13:27
首先，这题是assumption题。

作者想证明：

思路清晰了。谢谢Alzn。

在受重伤者中20%的人系了安全带。
在调查者中，如果整体只有18%的人系了安全带，就说明系安全带会更容易重伤。
因此A正确。

作者: RRZZR 时间: 2017-3-7 05:34
此题经典！我想了半天也没做对。。

作者: lisiberry 时间: 2017-3-7 06:25

RRZZR 发表于 2017-3-7 05:34
此题经典！我想了半天也没做对。。

还好还好，看来问的还是挺有水平的

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