___at the door ,i'v hardly rung the bell ____ the door opened.为什么用standing ,before?

问题描述:

___at the door ,i'v hardly rung the bell ____ the door opened.为什么用standing ,before?

Standing at the door, I had hardly rung the bell before / when the door opened.
standing 现在分词作伴随状语
hardly ....when/ before 表示一....就...
站在门口,我刚一按门铃,门就开了。

1)standing 是属于现在分词.语法规定,如果动词要做主语,不能用原形,只能用ing形式或不定式(to do),这里不能用不定式是因为不定式表示目的,而这里表示当时的状态就是正在站在门口,所以用ing形式.2)hardly .when/ ...