Use the correct tense or form of the verbs in parentheses:
11. This letter needs.............immadiately. Will you take care of it? (send)
12. It's a difficult question. I wish I ...................the answer. (know)
13. Would you mind .............the door? (close)
14. It's an exciting play. I ..................it twice already. (see)
15. The advantage of living in the countryside is that the air is..........(pollute)
16. .............................., they were very eager to make a good impression. (nature)
17. The sneakers were very smart, but they were.......................(comfort)
18. They are planning to protect the forests from..........................(forests)
19. Thank you very much for your............. organization. (value)
20. The next stage in the development of television is.........TV.(interact)
11. sending
12. knew
13. closing
14. have seen
15. unpolluted
16. Naturally
17. uncomfortable
18. deforestation
19. valuable
20. interactive