Question

【题目】He should brush his teeth before ______ to bed .

A. goB. goingC. to goD. went

Answer 1

【答案】B

【解析】

句意：在睡觉前他应该刷牙。根据before介词，后用动名词doing形式；go动词原形，going动名词或现在分词，to go不定式，went过去式；故选B。