11. Father was shaving and singing a silly song at the same time.
12. What were you doing last night between 11 o’clock and midnight?
13. The teacher was writing something on the blackboard while the children were throwing paper balls at one another.
14. She broke down when she heard the news.
15. I thought about their proposal all night but I couldn’t make any decision.
16. I saw Lisa Minelli in the theatre last night. She sat in the first row.
17. We flew over the desert when the engine stalled.
18. They were working very hard when the inspector entered.
19. The tyre blowed up when she drove on a deserted country road.
20. She was taking a shower when the snake creeped into the bathroom.
