22.What were you doing 　　　　I knocked at the door ?

21.Have a look at that man 　　　　you pass him .

20.Things have changed a lot 　　　　I wrote to you last time .

19.I waited 　　　　he had finished his work .

18.Tom’s mother had been a teacher 　　　　she married .

17.I didn’t go to bed 　　　　my father came back .

16.　　　 　she got home ,she began to wash her clothes .

15.　　　 　I had done my homework ,I went home .

14.　　　 　I was walking in the park ,I met Tom .

13.She has made greater progress 　　　　we expected .