介绍:
时间状语从句2--过去的2个动作先后发生，早的使用过去完成时（had +过去分词），晚的使用一般过去时
常用连词：after、before、when、as soon as、by the time、the minute……
例句：
The children ran away after they had broken the window.
I asked the price of the car, but they had already sold it.
I ran to the platform quickly, but the train had already left.
