Ответ:

2. Were talking

3. Noticed

4. Said

5. Didn't believe

6. Decided

7. Opened

8. Entered

9. Were going

10. Heard

11. Turned

12. Saw

13. Screamed

14. Ran

15. Were running

16. Looked

17. Spotted

18. Didn't know

19. Returned