But people now live longer than they 36 . Yet, all living things still show the 37 of aging, which will eventually 38 death. Aging is not a disease, but as a person passes maturity (成熟期), the cells of the body and the 39 they form do not function as well as they 40 in childhood and teenage years. The body provides less 41 against disease and is more 42 to have accident. A number of related causes may 43 aging. Some cells of the body have a fairly long life, but they are not 44 when they die. As a person ages, 45 of brain cells and muscle cells decreases. 46 body cells die and are replaced by new cells. In an aging person the 47 cells may not be as workable or as capable 48 growth as those of a young person. Another 49 in aging may be changes within the cells 50 . Some of the protein chemicals in cells are known 51 with age and become less elastic (有弹性的). This is why the skin of old people wrinkles (皱纹) and 52 . This is also the reason why old people 53 in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as DNA and RNA, store and 54 information that the cells need． Aging may affect this 55 and change the information-carrying molecules so that they do not transmit the information as well. 36. A．would B．be used to C．used to D． used 37. A．function B．effect C．affect D． sign 38. A．lead in B．give in C．run into D． result in 39. A．hands B．feet C．heart D． organs 40. A．do B．has done C．did D． had done 41. A．energy B．protection C．vigor D． power 42. A．likely B．probable C．possible D． alike 43. A．attend to B．contribute to C．add to D． devote to 44. A．replaced B．reborn C．recovered D． surrendered 45. A．a number B．the amount C．the number D． a great deal 46. A．The others B．The other C．Another D． Other 47. A．old B．left C．new D． other 48. A．to B．for C．of D． in 49. A．factor B．effect C．reason D． element 50. A．for themselves B．of themselves C．themselves D． on their own 51. A．change B．to have changed C．to change D． to be changed 52. A．hangs loose B．hangs loosely C．is hanging loosely D． is hanging loose 53. A．increase B．shrink C．lengthen D． decrease 54. A．pass away B．pass by C．pass off D． pass on 55. A．improvement B．procession C．approach D． process

Throughout history man has had to accept the fact that all living things must die. But people now live longer than they   36  . Yet, all living things still show the   37   of aging, which will eventually   38   death.

Aging is not a disease, but as a person passes maturity (成熟期), the cells of the body and the  39  they form do not function as well as they   40   in childhood and teenage years. The body provides less   41   against disease and is more   42   to have accident.

A number of related causes may   43   aging. Some cells of the body have a fairly long life, but they are not   44   when they die. As a person ages,   45   of brain cells and muscle cells decreases.   46   body cells die and are replaced by new cells. In an aging person the   47  cells may not be as workable or as capable   48   growth as those of a young person.

Another   49   in aging may be changes within the cells   50   . Some of the protein chemicals in cells are known   51   with age and become less elastic (有弹性的). This is why the skin of old people wrinkles (皱纹) and   52  . This is also the reason why old people   53   in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as DNA and RNA, store and   54   information that the cells need． Aging may affect this  55  and change the information-carrying molecules so that they do not transmit the information as well.

36. A．would          B．be used to C．used to     D． used

37. A．function          B．effect         C．affect         D． sign

38. A．lead in           B．give in         C．run into     D． result in

39. A．hands           B．feet C．heart        D． organs

40. A．do             B．has done          C．did           D． had done

41. A．energy         B．protection      C．vigor             D． power

42. A．likely             B．probable         C．possible    D． alike

43. A．attend to        B．contribute to  C．add to     D． devote to

44. A．replaced        B．reborn   C．recovered      D． surrendered

45. A．a number        B．the amount   C．the number   D． a great deal

46. A．The others              B．The other              C．Another         D． Other

47. A．old               B．left                C．new             D． other

48. A．to                 B．for      C．of                D． in

49. A．factor            B．effect              C．reason   D． element

50. A．for themselves          B．of themselves   C．themselves         D． on their own

51.   A．change            B．to have changed  C．to change          D． to be changed

52. A．hangs loose   B．hangs loosely     C．is hanging loosely D． is hanging loose

53. A．increase          B．shrink     C．lengthen         D． decrease

54. A．pass away      B．pass by            C．pass off           D． pass on

55. A．improvement           B．procession      C．approach       D． process