No one really knows how and why people change as they get older. Also, no theory sufficien

No one really knows how and why people change as they get older. Also, no theory sufficiently explains all the changes of the aging process. Aging is a plex and varied process that varies in how it affects different people and organs. In fact, even in one person , different organ systems “age “ at a different rate.
At a certain point in our lives our body systems will begin to weaken . It may bee more difficult for us to see and hear. The slow change of aging causes our bodies to lose some of their ability to bounce back from disease and injury. In order to live longer , we have always tried to slow or stop this change that leads us toward the end of our lives.
Many factors decide our health . A good diet plays an important role. The amount and the type of exercise we get are another two factors. Our living condition is yet another. But scientists studying the aging problem want to know: Why do people grow old? They hope that by studying the aging medical science they may be able to make the length of life longer.
There is nothing to be afraid of as the old age es. Many consider the later part of life to be the best time for living. Physical activity may bee less, but often we get better understanding of the world and ourselves.
What we consider the old age now may only be middle-aged some day soon. Who knows ,with so many advances in medical science happening so quickly, life length may one day be measured in centuries ,rather than in years!
【小题1】The underlined phrase “bounce back ”means “    .”A．jump backwardB．run fastC．preventD．recover【小题2】In order to make people live longer, scientists     according to the text.A．teach people how to eat properlyB．discover how important the exercise is to one’s healthC．study the ways to slow or stop the process of agingD．invent new medicine to slow down the process of aging【小题3】 Many consider the later part of life to be the time of living because they    .A．consider their lives have been very successfulB．have e through the battle of life safelyC．know more about themselves and the outside worldD．can have a good rest and enjoy themselves【小题4】How many factors which decide our health are mentioned in the text?A．TwoB．FourC．FiveD．SixD