17. While I __________ (paint) the room, I _____________ (fall) off the ladder.
was painting / fell
18. He ________ (cook) dinner when someone _________ (knock) on the door.
was cooking / knocked
19. They _____(sit) in the living room when they _______ (hear) the music outside.
were sitting / heard
20. The guests ____________ (arrive) while I _________ (decorate) the cake.
arrived / was decorating
21. The children _________ (build) a sandcastle when a wave __________ (wash) it away.
were bulding / washed
22. I ____________ (fall) asleep while I ____________ (listen) to music
fell / was listening
