I.

1.A

2.D

3.D

4.B

5.C

II.

1.C

2.D

3.A

4.A

5.B

III.

1.although

2.come

3.were

4.solar

5.how much

6.unpolluted

IV

1.hot

2.carelessly

3.disappointed

4.depth

5.skillful

6.celebrations

7.depended

8.careful

9.nutural

10.polluted

V

1.haven't finished

2.were written

3.spent

4.watching

5.was surfing

6.have lived

7.burning

8.don't save - will be

9.solving

Bài 1 :

1. a

2. d

3. d

4. b

5. d

Bài 2 :
1, C

2, D

3, A

4, A

5, B

Bài 3 :

1. Even

2. will come

3. were

4, Solar

5, how much

6, unpolluted

Bài 4 :

1. heated

2. carelessly

3. disappointed

4. depth

5. skillful

6. celebration

7, dependence

8. careful 

9. natural

10. polluted

Bài 5 :

1. haven't finished

2. were written

3. spent

4, watching

5, was surfing

6, have lived

7, burning 

8, don't save - will be

9, solving