完形填空 Throughout history man has had to accept the fact that all living things must die. But peop

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完形填空 Throughout history man has had to accept the fact that all living things must die. But people now live

longer than they__1__.Yet, all living things still show the__2_of aging, which will eventually__3__death.

Aging is not a disease, but as a person passes maturity (成熟期), the cells of the body and the__4__

they form do not function as well as they__5__in childhood and teenage years. The body provides less

__6__against disease and is more__7__to have an accident.

A number of related causes may__8__to aging. Some cells of the body have a fairly long life, but they

are not__9__when they die. As a person ages, 10 of brain cells and muscle cells decreases. 11

body cells die and are replaced by new cells. In an aging person the 12 cells may not be as workable

or as capable 13 growth as those of a young person.

Another 14 in aging may be changes within the cells 15 . Some of the protein chemicals in cells are

known 16 with age and become less elastic (有弹性). This is why the skin of old people wrinkles and

17 . This is also the reason why old people 18 in height. There may be other more important chemical

changes in the cells. Some complex cell chemicals, such as DNA and RNA, store and 19 information

that the cells need. Aging may affect this 20 and change the informationcarrying molecules so that they

do not transmit the information as well.

( )1．A. would

( )2．A. function

( )3．A. lead in

( )4．A. hands

( )5．A. do

( )6．A. energy

( )7．A. likely

( )8．A. attend

( )9．A. replaced

( )10．A. a number

( )11．A. The others

( )12．A. old

( )13．A. to

( )14．A. factor

( )15．A. for themselves

( )16．A. change

( )17．A. hangs loose

( )18．A. increase

( )19．A. pass away

( )20．A. improvement

B. be used to

B. effect

B. give in

B. feet

B. has done

B. protection

B. probable

B. contribute

B. rebuilt

B. the amount

B. Others

B. left

B. for

B. effect

B. of themselves

B. to have changed

B. hangs loosely

B. shrink

B. pass by

B. procession

C. used to

C. affect

C. run into

C. heart

C. did

C. vigor

C. possible

C. add

C. recovered

C. the number

C. Another

C. new

C. of

C. reason

C. themselves

C. to change

C. is hanging loosely

C. lengthen

C. pass off

C. approach

D. used

D. sign

D. result in

D. organs

D. had done

D. power

D. alike

D. devote

D. surrendered

D. a great deal

D. Other

D. other

D. in

D. element

D. on their own

D. to be changed

D. is hanging loose

D. decrease

D. pass on

D. process