- Why do you often take exercise? me keep fit.A. HelpB. HelpingC. To helpD. helped

问题补充：

--- Why do you often take exercise? --- me keep fit.

A. Help

B. Helping

C. To help

D. helped

答案：

(答案→)A. Help

B. Helping

C. To help

D. helped

解析：句意：你为什么常常做锻炼？——有助于我保持身体健康。下文省略的逻辑主语exercises，复数形式，只保留了谓语部分。结合语境可作描述的是客观性动作，用一般现在时态，故选A。