1) Liz was dusting the furniture when she broke a vase.
2) Irene was playing with a kitten while her mother was speaking to her friend.
3) The students were listening attentively while the professor was giving a lecture.
4) When Den returned home his little sister was watching some cartoons on TV.
5) While Martin was playing the guitar, the girls were singing.
6) I was waiting for a bus when Frank stopped his car at the bus stop.
7) Sam and Vicky were speaking to the waiter when we came into the café.
8) While the doctor was writing some prescription, Tim was taking the temperature.
9) The boys were fighting when I came up to them. 10) You were having lunch while I was discussing this question with the boss.
