1.He is the cleverest student in my group.

2.She can't stay longer than 30 minutes.

3.It's the best holiday I' ve had.

4.Well, the place looks cleaner now.

5.The red shirt is better but it's more expensive than being a builder.( câu này mình thấy bạn ghi đề sai thì phải?!)

6.l'll try to finish the job more quickly than the white one.

7.Being a firefighter is more dangerous than being a builder.

8.Lan sings more sweetly than Hoa.

9.This is the most exciting film I've ever seen.

10.He runs the fastest of all.

11.My Tam is one of the most popular singers in my country.

12.Which planet is  the closest to the Sun?

13.Carol sings as beautifully as Mary,but Cindy sings the most beautifully

14.The weather this summer is even hotter than last summer.

15.Your accent is worse than mine.