单选题
The age-old riddle of why many women live longer than men has been solved. It's their pumping power, British researchers have found. On average, women live five years longer than men and women over the age of 60 are now the fastest-growing section of the British population. The average male heart becomes weaker with age, and by the age of 70 its power to pump blood around the body could have decreased by up to a quarter of its youthful strength. David Goldspink, Professor of Cell and Molecular Sports Science at Liverpool John Moores University, said yesterday that women's longevity is linked to the strength of their hearts. Unlike men, they pump just as strongly at 70 as they do at 20. "We have found that the power of the male heart falls by 20 -25 percent between 18 and 70 years of age," Professor Goldspink said. "In stark contrast, over the same period there was no age-related decline in the power of the female heart, meaning that the heart of a healthy 70-year-old woman could perform almost as well as a 20-year-old's." The dramatic difference between the sexes might explain why women live longer. The good news is that men of any age can improve the health of their hearts simply by taking more regular exercise.
单选题
Why do women live longer than men? ______
【正确答案】
A
【答案解析】[解析] 由文中第一段的第二句话“The age-old riddle of why many women live longer than men has been solved. It's their pumping power”可以总结出男性和女性的寿命差异与心脏的活力有关，同时根据第二段的数据对比可知，女性比男性的寿命长是因为女性的心脏活力好于男性。因此A选项符合题意。
单选题
Male's heart power to pump blood around the body could have decreased by ______of its youthful strength.
【正确答案】
C
【答案解析】[解析] 由文中第二段的最后一句话“The average male heart becomes weaker with age, and by the age of 70 its power to pump blood around the body could have decreased by up to a quarter of its youthful strength”可知，男性心脏的力量在70岁时比年轻时降低a quarter，即“四分之一”。因此C选项为正确答案。
单选题
Women's longevity is because of______.
【正确答案】
B
【答案解析】[解析] 文章第三段“...said yesterday that women's longevity is linked to the strength of their hearts”告诉我们，女性的寿命长跟她们的心脏力量有关系。所以B为正确答案。
单选题
A 70-year-old woman's heart's pumping power is ______a 20-year-old woman.
【正确答案】
C
【答案解析】[解析] 文中这句话“...meaning that the heart of a healthy 70-year-old woman could perform almost as well as a 20-year-old's”告诉我们，一名健康的70岁女性的心脏力量与一名20岁女性的心脏力量是一样的。所以C选项符合题意。