1.->When Don arrived , we were having coffee.
2.->He sat down on the chair while I was painting it.
3->The students were playing a game when the professor arrived
4.->Felix phoned the fire brigade when the cooked caught on fire.
5.->While Henry was walking in the mountains, he saw a bear.
6.->The race began when the starter fired his postol.
7.->I was walking to home when it started rainning.
8.->When Margaret was openning the door, the phone rang.