Use Simple Past or the Past Perfect.
1. She (just/fold) the pink apron and placed it in a table drawer when the door (open) and Joe (enter).
2. The police wanted to know why he (bring) a gun to school.
3. We (wait) until the match (finish).
4. Why (not / he / ask) her to wait and think again before she (leave) Paris.
5. He was wondering why he (let) her leave so easily.
6. He (have to) go to work by bus because his car (break) down.
7. He knew he (earn) that money with a great difficulty.