I:

1B 

2B

3C

4B

5C

II:

1A (if 1)

2B (if 3)

3C (if 3)

4B (if 2)

5A (if 2)

III:

1. John is the most clever student in my class (so sánh nhất với tính từ dài)

2. The kitchen is bigger than the living room (xó sánh hơn với tính từ ngắn)

3. In spite of his good salary, he was unhappy with his job.

IV.

I think learning English is one of the most important things we should do because language is an international language . If we learn English well, we will have more opportunity to get a get a good job with high salary. More, we can communicate with all over the world and have a lot of foreign friends. In short, learning English has a various advantages.

I,

1, B 

2, B

3, C

4, B

5, C

II,

1, A 

2, B 

3, C 

4, B

5, C

III,

1,John is the most clever student in my class 

2,the kitchen is bigger than the living room 

3,in spite of his good salary, he was unhappy with his job