Sure! Here are the rewritten sentences:

1. My school is the same as yours.
2. Your school is not the same as mine.
3. Hoa and Tim are both 13 years old. (same age)
4. Tim is the same age as Hoa.
5. I am quite tall, but you are taller (than me).
6. I'm not.
7. My book is not as interesting as yours.
8. Your book is.
9. The exam was more difficult than we thought.
10. The exam was not easy.
11. He is more careless than me. (careful)
12. Reading is not as boring as watching TV.
13. Watching TV is as boring as reading.
14. Ho Chi Minh is the biggest city in Vietnam.
15. Another city in Vietnam is as big as HCM.
16. No one in this class is as tall as Tam.
17. Tam is the tallest in this class.
18. He drives more carefully than I do.
19. I don’t.
20. Huan is a better swimmer than Lan.
21. Lan can’t.
22. He is the fastest runner in the race.