单选题 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, the cells of the body and the (39) they form do not function as well as they (40) in childhood and adolescence (青春期). The body provides less (41) against disease and is more prone (42) accident.
A number of related cause 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 decrease, (46) body cells die and are replaced by new cells. In an aging person the (47) cells may not be as viable (能生存的) 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. This is why the skin of old people wrinkles and (52) . This is also the reason old people (53) in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as RNA, store and (54) information that the cell need. Aging may affect this (55) and change the information carrying molecules so that they do not transmit the information as well.

单选题 A. use to B. be used to C. used to D. had
【正确答案】 C
【答案解析】used to表示“过去经常出现的情况”，因此选C。
单选题 A. function B. effect C. influence D. sign
【正确答案】 D
【答案解析】sign of aging即“老年化的迹象”，show要求的对象有外在的特征。
单选题 A. end in B. yield to C. result from D. result in
【正确答案】 D
【答案解析】result in death即“导致，造成死亡”；result from意为“由……引起的结果”；end in指“以……告终”：yield to含义为“屈服”。
单选题 A. arms B. feet C. heart D. organs
【正确答案】 D
【答案解析】organ，arm，heart和feet都属于人的生理机体，但organs可以概指人的器官。
单选题 A. do B. has done C. did D. were doing
【正确答案】 A
【答案解析】这里说的是一般情况，应用一般现在时形式。
单选题 A. strength B. protection C. vigor D. alertness
【正确答案】 B
【答案解析】provides less protection against disease指“不能提供足够的保护来防御疾病”。protect(ion) against是个习惯的搭配。
单选题 A. to B. for C. against D. in
【正确答案】 A
【答案解析】be prone to意为“likely to suffer something undesirable”。例如：Women are more prone to this disease妇女更容易患这种疾病。
单选题 A. concern to B. contribute to C. happen to D. bring to
【正确答案】 B
【答案解析】contribute to意为“促成，有助于”，此句意为：“许多相关的因(原)素都会促成人的老化。”
单选题 A. replaced B. reborn C. recovered D. yielded
【正确答案】 A
【答案解析】replaced意为“替代”，该句意为：“某些细胞一旦死亡就再也没有了。”
单选题 A. a number B. the amount C. the number D. most
【正确答案】 C
【答案解析】the number of后接可数名词复数。
单选题 A. the B. the other C. old D. other
【正确答案】 C
【答案解析】根据句意“原来机体内的细胞死亡，并且被新细胞所取代”，因此选项C符合句中语义，故选old。
单选题 A. old B. remaining C. new D. other
【正确答案】 C
【答案解析】根据句意“在老年人当中，新细胞的生存和生长也许不如年轻人”，因此，选项C符合句中语义，故选new。
单选题 A. to B. for C. of D. with
【正确答案】 C
【答案解析】介词of与be capable搭配，构成固定词组be capable of sth．。
单选题 A. factor B. effect C. reason D. element
【正确答案】 A
【答案解析】effect意为“效果”，reason意为“原因”element意为“要素，特色”，均不符合句意。只有factor“因素”符合句意，故选C。
单选题 A. for themselves B. by themselves C. themselves D. on their own
【正确答案】 C
【答案解析】直接用反身代词反指。
单选题 A. change B. changing C. to change D. being changed
【正确答案】 C
【答案解析】“Some of the protein chemicals in cells are known to change with age”等于“People know that some of the protein chemicals in cells change with age”。
单选题 A. hangs loose B. hangs loosely C. is hanging loose D. is hanging loosely
【正确答案】 A
【答案解析】hangs loose是个“系+表”结构，表语说明主语，应用形容词。同样的例子有turn yellow和run dry等。
单选题 A. shorten B. shrink C. lengthen D. decrease
【正确答案】 D
【答案解析】shrink意为“to become smaller”，而这里已指明是“in height”，因此应使用decrease。
单选题 A. pass to B. pass on to C. pass from D. pass on
【正确答案】 D
【答案解析】pass on information意为“传递(输)信息”。
单选题 A. method B. procedure C. development D. process
【正确答案】 D
【答案解析】信息传递是个过程，故应选用process。