Verified answer

1 She saw (увидела - однократное быстрое действие) the police car when she was driving (действие в процессе) to work.

2 I was making dinner (процесс) when suddenly the saucepan of oil burst into flames!

3 She was looking out of the window when she saw the crash.

4 The teacher came into the room while we were playing a game.

5 While I was taking my dog for a walk it began to rain.