英语句型中的疑问Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.when disturbed in their hiding places 中的 disturbed 为被动形式,但是前面为什么没有系动词?

问题描述:

英语句型中的疑问
Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.when disturbed in their hiding places 中的 disturbed 为被动形式,但是前面为什么没有系动词?