I
1. A class
2. A polluted
3. C bear
4. A earth
5. B anything
6. D answer
II
1. A because ( + S + V: bởi vì )
2. D do
3. B doctor robot
4. C must
5. C because ( + S + V: bởi vì )
6. D ( nhưng )
7. B don't
8. A reduce ( giảm )
9. A is - will go ( If 1 : If + S1 + Vs/es, S2 + will + Vinf )
10. B have been ( 3 times : hiện tại hoàn thành )
11. D britain
12. A national television
13. B has gone
14. B has bought
15. D or ( hoặc )
16. C sporty
17. B got
18. D for ( khoảng thời gian )
III
1. will go
2. to do
3. Have - seen
IV
1. B stays -> stay
2. C older -> oldest
