We were doing our homework when the lights went out.改为同义句

We were doing our homework when the lights went out.改为同义句
We were doing our homework ____ ____ ____ the lights went out.
用所给词正确形式填空
Father _____ still _____ (sleep) when I ______(get) up yesterday morning.
Doctor Liu was on duty last night.He _____ still _____(work) in the hospital at 10 p.m.
Mr.Wang spends a lot of time writing his novel every day.He ____ still ____(work) at midnight last night.