Here are the transformed sentences:

6. **Do you have a better television than this?**
-> Is this **the best television you have?**

7. **Nam likes drinking orange juice.**
-> Orange juice **is liked by Nam.**

8. **Let's go to the restaurant for dinner tonight.**
-> Why **don’t we go to the restaurant for dinner tonight?**

9. **The movie theater is near the city center.**
-> The movie theater is not **far from the city center.**

10. **That motorbike belongs to Mr. Nam.**
-> Mr. Nam **is the owner of that motorbike.**

Feel free to ask for any adjustments if needed!