题目内容

11、 Experts say that the rate at which one ages ______ from person to person and is usually influenced by a number of factors. 

A. is varying         B. varied             C. has varied           D. varies

试题答案

11、D.

解析： 考查谓语动词的形式。句意为：专家称，人衰老的速度因人而异。衰老通常受多因素的影响。空白处的动词应与主句的动词和从句的第二个谓语的动词形式一致，即用一般现在时。因从句的主语是the rate，故谓语用varies。