I.
1. took; 2. would repair; 3. had left; 4. were doing; 5. had happened; 6. lent; 7. was opened; 8. was trying; 9. slipped; 10. woke; 12. had broken; 13. was waiting.
II.
14. the; 15. -; 16. a; 17. a; 18. -; 19. the; 20. -; 21. -; 22. -; 23. the; 24. the; 25. the.
III.
26. at; 27. for; 28. from; 29. next to; 30. on; 31. of; 32. to; 33. of; 34. for.
IV.
35. celebration; 36. explosions; 37. historical; 38. government; 39. criminal.
V.
40. either; 41. latest; 42. do; 43. anybody; 44. a few
VI.
45. ..., isn't there?
46. ..., so did Jane.
47. Mr. Wren is good at doing his job.
48. The trip was exciting but expensive.
49. My book is different from yours, mine has a vocabulary.
50. ..., and Maria hasn't either.