| Throughout history man has had to
accept the fact that all living things must die, hut people now live longer than
they used to. Yet, all {{U}} (62) {{/U}} things still show the effect of
aging, which will eventually {{U}} (63) {{/U}} death. The body and the
{{U}} (64) {{/U}} , they do not function as well as they {{U}} (65)
{{/U}} in childhood and adolescence(青春期). The body provides less
{{U}} (66) {{/U}} against disease and is more prone(易于……的) {{U}} (67)
{{/U}} accident. A number of related causes may {{U}} (68) {{/U}} to aging. Some cells of the body have a {{U}} (69) {{/U}} long life, but they are not {{U}} (70) {{/U}} when they die. As a person ages, {{U}} (71) {{/U}} of brain cells and muscle cells decreases. Other body cells did and are replaced by new cells. In an aging person the {{U}} (72) {{/U}} cells may not be as v A. made B. did C. grew D. had 我来回答: 提交
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