Past Continuous vs Past Simple

What ............ you doing when the accident happened?

What ............ Mr Magnus doing when you saw him?

I ............ (drive) home when I had an accident.

Sue ............ (water) the plants when she saw a beautiful butterfly.

At five o'clock, Tom ............ (sit) in his room and playing video games.

I was walking to school when I ............ (see) the accident.

While I ............ (paint) the ceiling, the ladder moved and I fell.

When I was walking home, I ............ (meet) Julie.

We ............ (play) tennis when John slipped and twisted his ankle.

When I arrived, they ............ (sit) on the sofa and talking.