=>
43. weren't
44. were
45. hadn't spend
46. I wish I were in a secluded beach in Mexico.
47. I wish you wouldn't say things like that.
48. I really wish I had invited her to the party.
49. I wish I could help you do your homework.
50. She wishes she didn't work with him.
5/
1. could -> must ( must have been very sad : ắt hẳn rất buồn)
2. would -> had ( had better = should)
3. will join -> can join (Nếu bạn rảnh hôm nay, bạn có thể tham gia bữa tiệc của chúng tôi tại câu lạc bộ.)