专四专八考试

【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 (31) . However, all living things still show the (32) of aging, which will eventually (33) death.Aging is not a disease, but as a person passes maturity, the cells of the body and the (34) they form do not function as well as they (35) in childhood and adolescence. The body provides less (36) against disease and is more inclined (37) accident.A、number of related causes may (38) aging. Some cells of the body have a fairly long life, but they are not (39) when they die.As a person ages, (40) of brain cells and muscle cells decreases. (41) body cells die and are replaced by new cells. In an aging person the (40) cells may not be as viable or as capable (43) growth as those of a young person.Another (44) in aging may be changes within the cells (45) . Some of the protein chemicals in the cells are known (46) with age and become less elastiC、This is why the skin of old people wrinkles and (47) . This is also the reason old people (48) in height.
There are maybe other more important chemical changes in the cells. Some complex cell chemicals, such asDNA, store and (49) information that the cells neeD、Aging may affect this (50) and change the information- carrying molecules so that they do not transmit the information as well.
A、do B、has done
C、did D、were doing
网考网参考答案：C
网考网解析：
[解析] 动词时态题。本句从句中谓语动词重复主句中的动词function，用动词do来代替，并且因为指代过去，所以用C did符合题意。其它选项均不正确。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>