My grandfather keeps healthy by for half an hour every morning.A. working outB. acting ou

问题补充：

My grandfather keeps healthy by for half an hour every morning.

A. working out

B. acting out

C. taking out

D. looking out

答案：

(答案→)A. working out

B. acting out

C. taking out

D. looking out

解析：动词短语辨析。work out锻炼；算出；，理解；制定出；act out将…表演出来；（用行动）表示出来;take out取出；割掉；拔去；取得；擦掉；look out当心；句意：我的祖父每天早晨锻炼半小时，以保持健康。