Here are the tag questions for the sentences:

8. There are 4 people in my family, **aren't there?**
9. It seems that this river is polluted, **doesn't it?**
10. You don't know Jack Smith, **do you?**
11. Hai can play the piano, **can't he?**
12. I'm your friend, **aren't I?**
13. She thought that Jim loved her, **didn't she?**
14. Everything is ok, **isn't it?**
15. Nobody called on the phone, **did they?**
16. They couldn't understand him, **could they?**
17. You go to school today, **don't you?**
18. She doesn't eat meat, **does she?**
19. There wasn't enough time, **was there?**
20. No salt is allowed, **is it?**
21. Neither of them complained, **did they?**
22. Let's sing karaoke, **shall we?**
23. Turn on the light, **will you?**
24. He has helped nobody, **has he?**
25. The children don't want to go to bed early, **do they?**
26. The movie received several Oscars, **didn't it?**
27. Mary seldom wears her dress, **does she?**
28. Tom and Jerry can't live in peace, **can they?**
29. The John family used to live in Liverpool, **didn't they?**
30. Mr. Bao said that we should use solar energy, **didn't he?**
31. Your aunt must be happy, **mustn't she?**
32. That wasn't my fault, **was it?**
33. My uncle hardly gets up late, **does he?**
34. The lands must be very beautiful, **mustn't they?**
35. I am cowardly, **aren't I?**