用合适的形式填空。
1. The children _____________ (sleep) when the fire alarm _________ (ring) last night.
2. I _____________(read) a storybook when my mum _______ (come) into my room.
3. On Monday at 6:00 pm, Mary and I _____________ (have) dinner in a restaurant.
4. I _____________ (watch) TV with my family when you ________ (call) me.  
5. Bob _____________ (do) martial arts in the gym when he _____ (hear) the exciting news.
6. We _____________ ( cheer ) at the park when the bells _____________ ( ring ) .