企源知识库

Tom, _____ where to find the book, asked his mother where the book was.
A、not knowing
B、not to know
C、knowing not
D、unknowing
【正确答案】：A
【题目解析】：本题考察现在分词作状语，Tom和know之间是主动的关系，所以用knowing，否定形式在前面加not，故选A。