1. When I was doing the washing-up, I broke a plate.
2. While Tom was playing the piano, his mother was doing the washing-up
3. a: what were you doing when you heard that noise?
B: I was trying to change a light bulb that jad burnt out
4 I was having dinner when I suddenly heard a loud bang
5. My father was working in the garden when an old friend passed by to see him