选择题：______when to start out,he went to ask his captain

Question

when to start out,he went to ask his captain
1.Not to know 2,Don't know 3,Not knowing 4,Not known
主要请解释这句话的结构！

Answer 1

Not knowing 是对的。这个句子只有一个主语，也只能只有一个谓语，前面的只能是非谓语，对于主语来说非谓语又是主动地，所以用ing的形式。

Answer 2

3,Not knowing

Answer 3

3