——What should I do ,doctor ——____ healthy ,you should take more exercise.

题目

——What should I do ,doctor ——____ healthy ,you should take more exercise.
A.Keep B.Keeping C.To keep D.Having kept
,为什么?

答案

to keep healthy（to do)动词不定式作目的状语,表示为了.,这里指为了保持健康,你应该做更多的锻炼.