请教NN们一道GWD26-Q37，3号就考，着急。。谢。。。

Cherliuiking

When people engage in activities that help others, their brain releases endorphins, the brain’s natural opiates, which induce in people a feeling of well-being. It has been suggested that regular release of endorphins increases people’s longevity. And a statistic on adults who regularly engage in volunteer work helping others shows that they live longer, on average, than adults who do not volunteer. However, that statistic would be what we would expect even if volunteering does not boost longevity, because    .

A.    in the communities studied, women were much more likely to do regular volunteer work than men were, and women tend to live longer than men do.
B.    the number of young adults who do regular volunteer work is on the increase
C.    ! the feelings of well-being induced by endorphins can, at least for a time, mask the symptoms of various conditions and diseases, provided the symptoms are mild.
D.    it is rare for a person to keep up a regular schedule of volunteer work throughout his or her life.
E.    Some people find that keeping a commitment to do regular volunteer work becomes a source of stress in their lives.
这道题到底是选A还是选C呢？

gtr

When people engage in activities that help others, their brain releases endorphins, the brain’s natural opiates, which induce in people a feeling of well-being. It has been suggested that regular release of endorphins increases people’s longevity. And a statistic on adults who regularly engage in volunteer work helping others shows that they live longer, on average, than adults who do not volunteer. However, that statistic would be what we would expect even if volunteering does not boost longevity, because    .

A.    in the communities studied, women were much more likely to do regular volunteer work than men were, and women tend to live longer than men do.
B.    the number of young adults who do regular volunteer work is on the increase
C.    ! the feelings of well-being induced by endorphins can, at least for a time, mask the symptoms of various conditions and diseases, provided the symptoms are mild.
D.    it is rare for a person to keep up a regular schedule of volunteer work throughout his or her life.
E.    Some people find that keeping a commitment to do regular volunteer work becomes a source of stress in their lives.
这道题到底是选A还是选C呢？

-- by 会员 Cherliuiking (2010/1/29 12:36:59)

A is right


原文的一个潜在假设就是做义工的人群，和不做义工的人群，除了做不做义工之外，是一样的。
所以，如果做义工的人群活得长，那肯定就是做义工时候产生那个的endorphins 导致的。


A 就打破了人群一样的假设。换句话说，不管有没有endorphins ，因为做义工的人群本来就是长寿人群，他们就会活得长。


C只说了遮挡病症，但是还是解释不了长寿啊。