過去進(jìn)行式 (was/were + V-ing)
過去某一動作發(fā)生時(V-ed)正在進(jìn)行的另一動作(was/were + V-ing)
What were you doing when he came? 他來的時候你在做什么?
I was writing a report when he came. 他來的時候我正在寫報告。
What were they doing when the earthquake happened?
地震發(fā)生的時候他們在做什么?
They were watching TV when the earthquake happened.
地震發(fā)生的時候他們正在看電視。
My mother cut her finger while she was cooking.
我媽媽做菜時切到手指。
I was taking a nap when you called yesterday.
你昨天打電話來的時候我正在午睡。