1. was
2. is
3. is being packed
4. to do
5. Эм.. даже не знаю. Когда так говорят, то имеют ввиду "На столе лежат две книги", но если переводить буквально, то "Две книги на столе"
6. If I lived in New–York, I would go to the park every day.
7. множество литературных произведений
8. If you had called me yesterday, I would have helped you
9. why had I decided
10. her cousin is going to stay
11. not to buy
12. was situated
13. more interesting
14. as much
15. much more expensive
16. not as serious
17. must
18. should
19. play
20. to leave
21. трудные для решения, бессмысленные для обсуждения
22. вымирание, наносить вред/ущерб
23. is drinking
24. visit
25. Does/come