2.the 

3.the

4.a

5.the

6.the

7.the

8.the

9.a

10.the

11.the

12.the

13.the

14.the

15.a

16.the 

17.the 

18.an

19.the

20.the

21.the

II

1.longer/than

2.more painful than

3.older than

4.simpler than

5.more fluently than

6.more important than

7.cheaper than

8.more/more peaceful

III

1. That's the funniest story I've ever heard. 

2. It's the first mistake he's ever made.

3.That's the best coffee I've ever tasted for a long time.

4. This is the most uncomfortable bed I've ever slept

5. It's the biggest meal I've ever had

6.Ann is the most generous person I've ever met.

7. You are the best friend I've ever had.

8.This is the most difficult decision I've ever had for years.

IV

2. Who is the most famous singer in your country?

3. What is the most popular sport in your country?

4.What is the most expensive thing you've bought?

5. What was the happiest day in your life?

6.What is the most stupid thing you've ever done?

7. Who is the most intelligent person you know?

8. Who is the most beautiful person you know?