2. 职称英语
  3. Throughout history man has had to accept the fact that all living things mus

Throughout history man has had to accept the fact that all living things mus

游客2025-04-07  42
问题     Throughout history man has had to accept the fact that all living things must die. But people now live longer than they【C1】______. Yet, all living things still show the【C2】______of aging, which will eventually【C3】______death. Aging is not a disease,(but)as a person passes maturity, the cells of the body and the【C4】______they form do not function as well as they【C5】______in childhood and teenage years. The body provides less【C6】______against disease and is more【C7】______to have accident. A number of related causes may【C8】______aging. Some cells of the body have a(fairly)long life, but they are not【C9】______when they die. As a person ages,【C10】______of brain cells and muscle cells decreases.【C11】______body cells die and are(replaced)by new cells. In an aging person the【C12】______cells may not be as workable or as capable【C13】______growth as those of a young person. Another【C14】______in aging may be changes within the cells【C15】______. Some of the protein chemicals in cells are known【C16】______with age and become less elastic. This is why the skin of old people wrinkles and【C17】______. This is also the reason why old people【C18】______in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as DNA and RNA, store and【C19】______information that the cells need. Aging may affect this【C20】______and change the information carrying molecules so that they do not transmit the information as well. [br] 【C5】
选项 A、do
B、has done
C、did
D、had done
答案 C
解析 语法知识。分析句子结构可知，空格处指代的是前文提及function，句中in childhood说明时态为一般过去式，故应用助动词did代替function，故答案为C。
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