Question

【题目】They seem ______ what they are doing.

A. knew B. to know C. knowing D. know

Answer 1

【答案】B

【解析】

句意：他们似乎知道自己在做什么。A. knew过去式，知道；B. to know动词不定式； C. knowing现在分词或动名词；D. know动词，知道。seem动词，似乎、好像；根据seem to do似乎做某事，可知使用动词不定式形式。故选：B。