1. Ving用作非谓语时,对该动词是延续性动词还是瞬间性动词没有要求。 如:Having slept in bed for nearly two days, he felt tired. sleep是延续性动词 再如:Can you make him go to bed earlier? go to bed是瞬间性动词
2. 非谓语中的ing形式不一定只表示主动,当然还可以表示持续。 如:Please keep him studying in the classroom this afternoon.