非谓语的问题.______ what to do next,he turned to me for help.

问题描述:

非谓语的问题.______ what to do next,he turned to me for help.
______ (Not know)what to do next,he turned to me for help.
______(sleep)late in the moring,Bob turned off the alarm.
主句是过去式,那用非谓语的话应该用哪种形式?

Not knowing what to do next,he turned to me for help.
表示情形,用ing形式
To sleep late in the morning,Bob turned off the alarm.
当表示目的的时候,用to do.