I

1 B surface

2 A wanted

3 D laugh

4 B always

5 B knife

6 D humor

7 D report

8 C group

9 B revise

10 D safety

II

1 A themselves

2 B old enough to

3 C ought

4 B on

5 B hard

6 C playing

7 B to take

8 B to give

9 D. A and B

10 B to leave

III

1 He is intelligent enough to answer all the questions.

2 He isn't tall enough to reach the shelf.

3 She is good enough to pass the exam.

4 You aren't well enough to go to school.

5 They are sociable enough to make a lot of friends.

IV 

1 B to -> from ( different from: khác với )

2 C good -> well ( sau động từ speak cần trạng từ )

3 B reported -> report ( didn't + Vinf )

4 C for -> since ( last Sunday là mốc thời gian nên dùng " since " )

5 B went -> gone ( S+ have/ has + Vpp )

6 B staying -> stay ( ought to + Vinf )

7 B smoking -> smoke ( used to + Vinf )

8 C keep -> to keep ( ask someone + to V )

9 B differently -> different

10 C do -> doing ( interested in + Ving )

BT 1. 

1. a

2.a

3.d

4. c

5.d

6.d

7. c

8. b

9. b

10. b

BT2

1 c

2a

3b

4d

5c

6d

7b

8a

9c

10b

BT3

1b

2a

3b

4b

5c

6a

7a

8b

9c

10b