阅读理解 That question "why women live longer than men" can be answered at two levels. An evolutionary biologist would tell you that it is because women get evolutionary bonus points from living long enough to help bring up the grandchildren. Men, by contrast, wear themselves out competing for the right to procreate in the first place. That is probably true, but not much help to the medical profession. However, a group of researchers at John Moores University has just come up with a medically useful answer. It is that while 70-year-old men have the hearts of 70-year-olds, those of their female peers resemble the hearts of 20-year-olds. David Goldspink and his colleagues looked at 250 volunteers aged between 18 and 80 over two years. All the volunteers were healthy but physically inactive. The team''s principal finding was that the power of the male heart falls by 20-25% between the ages of 18 and 70, while that of the female heart remains undiminished. They found that between the ages of 20 and 70, men lose 1/3 of the contractile muscle cells in the walls of their hearts. Over the same period, women lose hardly any. There is a strong link between the number of these cells and the function of the heart. What remains a mystery is why men lose these cells and women do not. A previous theory of why women outlive men suggested that the female sex hormone, oestrogen, could have a protective effect on the heart. But Dr. Goldspink dismisses this idea, saying that there is no discernible drop-off in female heart function after menopause (更年期), when oestrogen (雌性激素) levels decrease dramatically. However, oestrogen does have a beneficial effect on blood vessels. The study found that blood flow to the muscles and skin of the limbs decreases with age in both sexes. The changes in the structure of the blood vessels occur earlier in men, but women catch up soon after menopause. It''s not all bad news for men, though. In a related study, the team found that the hearts of veteran male athletes were as powerful as those of inactive 20-year-old male undergraduates. But can men really recover lost heart function after a lifetime of inactivity and poor diet? Is it ever too late to start exercising? "I think the answer is no," says Dr. Goldspink. "The health benefits to be gained from sensible exercise are to be recommended, regardless of age." So if you are male and getting on, get on with it

单选题 A medical explanation as to the question why women live longer than men is that _________.

单选题 The power of the female heart remains undiminished between the ages of 18 and 70 probably because _________.

【正确答案】 A

【答案解析】推论题本题涉及事实间因果关系的推断。根据第三段我们知道，“20岁至70岁间的男人丧失了心壁收缩肌细胞的三分之一，而在同样阶段的女人几乎没有丧失收缩细胞。这些细胞的数量与心脏功能之间有密切的联系。”既然如此，我们可以推断，女性的心脏功能在18至70岁之间之所以保持不变很可能是因为女人没有丧失心壁收缩肌细胞。

单选题 Dr. Goldspink disagrees with the proposal that oestrogen could protect heart because _________.

单选题 What Dr. Goldspink says to men is that _________.

【正确答案】 C

【答案解析】细节题最后一段作者说道：对男人来说也不都是坏消息。相关的研究表明：退休的男性运动员的心脏与不好动的男大学生一样强有力。但是男人在过了一辈子不爱动、饮食差的生活之后真的能恢复心脏功能吗?开始锻炼晚不晚?对这两个问题，Dr，Goldspink的回答都是否定的。但是他建议说，无论什么年龄，合理的锻炼是有益的。综上所述，可以这么说：男人从年轻时就一直锻炼可以保持心脏不老，但一直不锻炼，老了要恢复丧失的年轻的心脏功能也是不可能的。但尽管如此，锻炼(对心脏)还是有好处的，所以应选C)。A)项不是作者所说的，B)项和D)项均与作者所说的相矛盾。