Ответ:

1. are disappeearing

2. know

3. cur down

4. destroy

5. don`t realise

6.are destroying

7.need

8.produce

9.eliminate

10.are the forest disappearing

11. agree

12. are cutting down

13.is causing

14. is also changing

15. is causing

16. is increasing

17.seems

18. are beginning

19. are trying

20. want