III:

1.making

2.have...ridden

3.go

4.seeing 

5.skateboarding

6.to spend

7.try

8.to improve

9.underline/to learn

10.doing

IV:

1.cheaper than

2.more effective

3.more beautiful than

4.more powerful than

5.taller than

6.heavier than

7.longer than

8.easier than

9.more comfortable than

10.more interesting                                                                           

11.more skillful

12.faster

13.earlier

V:

1.Hoa is the best in my class.

2.I adore collecting coins in my free time.

3.Nam has played soccer in 2005

4.He prefers watching TV more than he loves reading books.

6.Nick writes essays more carefully than Phuc.

7.A snail moves more slowly than a crab.

III.

1. making   2. have/ ridden   3. go    4. seeing    5. skateboarding   6. to spend

7. trying     8. to improve      9. underline  10. doing