Aging Throughout history man has had to accept the fact that all living things must die,but people now live longer than they use

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问题 Aging
Throughout history man has had to accept the fact that all living things must die,but people now live longer than they used to.Yet all living things still show the_________(1)of aging,which will eventually_________(2)death.
    Aging is not a disease,but as a person passes maturity,the cells of the body and the_________(3)do not function as well as they did in childhood and adolescence(青春期).The body provides less_________(4)against disease and is more likely_________(5)have accident.
  A number of related causes may_________(6)aging.Some cells of the body have a fairly long life,but they are not reborn when they die.As a person ages,_________(7)of brain cells and muscle cellsdecreases.The other cells are replaced by new cells.In an aging person the_________(8)cells andmuscle cells may not be as viable(能生存的)or as capable_________(9)growth as those of a young person.
  Another_________(1 0)in aging may be changes within the cells themselves.Some of the protein chemicals in cells are known_________(1 1)with age and became less elastic.This is why the skin of old people wrinkles and_________(12).This is also the reason old people_________(13)in height.Theremay not be other more important chemical changes in the cells.Some complex cell chemicals,such asDNA and RNA,store and_________(14)information that the cells need.Aging may affect this_________ (15)and change the information—carry molecules so that they do not transmit the information aswell.
(7)

选项 A、a number
B、the amount
C、the number
D、most

答案A

解析 B、C选项表示数量的多少,不能填到此处。most:表示大多数的意思,也不符合题意。因此,A选项为正确答案。
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