Why do men live a shorter life than women? The latest research indicates that men's hearts going into a rapid decline when they reach middle age could be the cause. The research of ageing on the heart has shown that women's _ may be linked to the fact that their hearts do not lose much pumping power with age. "We have found that the power of the male heart falls by 20-25 percent between 20 and 70 years of age," said the head of the study, Samantha of Liverpool John Moores University in the UK. "Within the heart there are millions of cells which make it beat.Between the ages of 20 and 70, one-third of those cells die and are not replaced in men ," said Samantha."This is part of the ageing process." What amazes scientists is that the female heart suffers very little loss of these cells.A healthy 70-year-old woman's heart could work almost as perfectly as a 20-year-old one's. "This gender  difference might give the reason why men live shorter than women,"said Samantha.They studied over 250 healthy men and women between the ages of 17 and 80, who are mainly healthy persons so as to reduce the influence of disease."The team has yet to think about why ageing suffers a greater loss on the male heart," said Samantha. But there is also good news -- men can enjoy the health of their hearts with regular exercise.Samantha stressed that women should also take regular exercise to stop their leg muscles getting weaker as they age. The text mainly talks about   _  .
men's heart cells women's ageing process the gender difference hearts and long life
Question: Why do men live a shorter life than women? The latest research indicates that men's hearts going into a rapid decline when they reach middle age could be the cause. The research of ageing on the heart has shown that women's _ may be linked to the fact that their hearts do not lose much pumping power with age. "We have found that the power of the male heart falls by 20-25 percent between 20 and 70 years of age," said the head of the study, Samantha of Liverpool John Moores University in the UK. "Within the heart there are millions of cells which make it beat.Between the ages of 20 and 70, one-third of those cells die and are not replaced in men ," said Samantha."This is part of the ageing process." What amazes scientists is that the female heart suffers very little loss of these cells.A healthy 70-year-old woman's heart could work almost as perfectly as a 20-year-old one's. "This gender  difference might give the reason why men live shorter than women,"said Samantha.They studied over 250 healthy men and women between the ages of 17 and 80, who are mainly healthy persons so as to reduce the influence of disease."The team has yet to think about why ageing suffers a greater loss on the male heart," said Samantha. But there is also good news -- men can enjoy the health of their hearts with regular exercise.Samantha stressed that women should also take regular exercise to stop their leg muscles getting weaker as they age. The text mainly talks about   _  .
A. men's heart cells
B. women's ageing process
C. the gender difference
D. hearts and long life
Answer: