阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案，并涂在答题卡相应的位置上。
Prolonging life (难度B/C级)来源：考试大
Scientists know that there are two basic approaches to prolonging life. One approach is the __1__ of the diseases that generally __2__ older people – diseases such as cancer, heart attack and stokes. __3__ is the delay of the process of growing old – the __4__ of the body.
In recent years scientific researchers have spent much time in the study of the process of aging. They believe __5__, within a few years, they will develop the knowledge and the __6__ to delay the aging process for 10 to 15 years. The __7__ will be that more people will live longer, more healthful lives. At present, scientists believe that __8__ the right diet, exercise, medical __9__, and mental attitude many people can live to be 100 years old.
Gerontologists, people who __10__ studies of the problems of growing old, are investigating __11__ body cells slow down and __12__ die. They feel that delaying this slowing down process would help postpone death. In a number of American universities, scientists are __13__ the activity of cells, the effects of diet and internal body temperature __14__ aging. If their studies are successful, the results should help improve the quality of life for older people in the next few years, __15__ increase the life span of the next generation.
1.
A) elimination B) deletion C) demonstration D) conduction
2.来源：考试大
A) effect B) affect C) reflect D) perfect
3.
A) Others B) Another C) The other D) One more
4.
A) decaying B) deleting C) decreasing D) weighing
5.
A) which B) what C) that D) having been
6.
A) capability B) capacity C) probability D) ability
7.
A) conclusion B) result C) summary D) sequence
8.
A) about B) over C) with D) on
9. 来源： 考试大
A) treat B) suggestion C) proposal D) advice
10.
A) major in B) engage in C) specialize in D) interest in
11.
A) why B) what C) that D) because
12.
A) considerably B) suddenly C) eventually D) actually
13.
A) discussing B) concerning C) studying D) searching
14. 来源：考试大
A) with B) on C) over D) within
15.
A) as much B) as much as C) so far as D) as well as
