20. Will be learning 21. To stay 22. Was leaving 23. Would built 24. Was managing 25. Will learning 26. To call 27. Was managing 28. Will had arrived 29. Will learning 30. To call 31. Has already left 32. Will cooking 33. To play 34. Were 35. Was finishing 36. Would live/were be 37. Will watching 38. To call 39. Will learning 40. Communicated 41. Were 42. To meet 43. Will learning 44. Communicated 45. Were 46. To meet 47. Will watching 48. To stay 49. Would invite

=>
21. to stay
22. had left
23. would build
24. had managed 
25. will be learning
26. to call
27. had managed 
28. arrived
29. will be learning
30. to call
31. had already left
32. will be cooking
33. to play
34. were
35. had finished
36. would lived/were
37. will be watching
38. to call
39. will be learning
40. had communicated
41. were
42. to meet
43. will be learning

44. had communicated
45. were
46. to meet
47. will be watching
48. to stay
49. would invite