答案是B. could是 情态动词 情态动词后面要跟动词原形 情态动词还包括了 will can should shall may might 等 但是这句话里 could是 从句what he …
一.Could是can的过去式 I could do it yesterday. 二．委婉的提出问题或陈述看法(主要是出于礼貌) 1. What could she be doing at this time of day? …
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