A hearty laugh relieves physical tension, your muscles relaxed for over half an hour.
A. to leave
B. left
C. leaving
D. leave
网友回答
A. to leave
B. left
(答案→)C. leaving
D. leave
解析：C 考察非谓语动词。句义：开怀大笑可以缓解身体紧张，至少可以使你的肌肉放松半小时。在题干中，空格处做伴随状语。且与逻辑主语laugh构成主动关系。C项我现在分词，表示主动，与题意相符。故C正确。