1. walked/was began;
2.What you was reading when they came in?
3.While I was diging in the garden ,I hurt my arm.
4.I waited for my flight yesterday morning.
5.How fast she drived when the accident was happening?
6.We were had a dinner when she called.
7.At 10.35 we played tennis in the club.
8.She writing letter at 6 p.m last evening.
9.Her father went to the art gallery when he was meeting her mother.
10.At 8.20 yesterday morning my mother drove me to the university.
11.They sat at the cafe at that time.
12.She was studying in the library when they suddenly called.
Не знаю правильно или нет,но хоть что-то.