9. Nam drives **more carefully** than yesterday.
10. They are **happier** than I am. 
11. Art is **easier** than Maths.
12. Hai Duong isn't **as noisy as** Ha Noi.
13. A new car is **better** than an old car.
14. An old car is **worse** than a new car.
15. He is **cleverer** than her.