1. longer -> longest
2. most convenient -> most convenient
3. taking -> take
4 highest -> higher
5. more -> most beautiful
6. incredibly -> incredible
8. longer-> the longest
9. or -> than
10. north -> northern
11. in -> on
12. mustn't be -> am not
13. more -> the most
14. better -> best
15. mustn't -> must
16. shouldn't -> should
17. give -> gives
18. helps -> help
19. and -> or
20. on -> in
II.
1. younger -> youngest
2. busyer -> busier
3. that -> than
4. china -> chinese
5. have -> has
6. smallest -> smaller
7. French -> France
8. biger -> bigger
9. is -> are
10. coldest -> the coldest