Câu trả lời:
1.the cleverrest
2.longer
3.the best
4.the cleanest
5.more expensive
6.quickly
7.more dangerous
8.sweeter8
9.the most exciting
10.the fastest
11.the most popular
12.closer than
13.beautiful, most beautiful
14.hotter
15.worse
16.better
17.biggest , biggest
18.more difficult, most difficult
19.largest