1. ...entered... had begun..
2. ...visited... lived...
3. told...had received...
4. ...remembered... had left...
5. had examined...
6. ...remembered... had left...
7. ..were...had past..
8. ...lived... had left...
9. ...opened... looked... tried... had happened...
10. ...understood... travelled..
11. ...came...had returned...
12. ...had worked...entered...
13. ...studied...entered...
14. ...said...had got..
15. ...wanted... had organized...
16. ...didn't know... had attacked...
17. ...was...had found...
18. ...remembered... hadn't rung...
19. ...read...had made...
20. ...left...hurried...
21... thought..had quarrelled..