1. He is ( clever ) the most clever student in my group
2. She can't stay ( long ) longer than 30 minutes
3. It's ( good )the best holiday I' ve had
4. Well, the place looks ( clean ) cleaner now
5. The red shirt is better but it's ( expensive ) more expensive than the white one
6. I'll try to finish the job ( quick ) is quickier
7. Being a firefighter is ( dangerous ) more dangerous than being a builder
8. Lan sings ( sweet ) is sweeter than Hoa
9. This is ( exciting ) the most exciting film I've ever seen
10. He runs ( fast ) is the fastest of all