1.While the children ___ (to draw), their parents ___(to watch) TV. *
2.What ____(to do) when you ___(to hear) the news? *
3.The students __(to open) their exercise books and ___(to start) witing. *
4.While we ___(to wait), we ____ (to do) crossword puzzles. *
5.He ____(to meet) a lot of friendly people before he ___(to move) to California. *
6.After Angela ____(to lock) the door, the school bus ____ ( to arrive). *
7.Cindy ___(to break) her leg while she ____ (to snowboard). *
8.When they ____(to come) to London, they ____(to visit) many museums and art galleries. *
9.My faher ____(to drive) at 70 km per hour when a policeman ____(to stop) him. *
10.He ____(to listen) to the radio while he_____( to prepare) breakfast. *
11.Hardly we ____(to finish) dinner when the doorbell ___(to ring). *
12. I __(to lose) my keys while I ___(to walk) to school. *