1. is -> are (vì letters có s)

2. is -> was (vì có yesterday => thì quá khứ)

3. was -> will be (vì có tomorrow => thì tương lai)

4. were being -> has been (now => thì hiện tại)

5. were -> is

6. is-> was (vì có yesterday => thì quá khứ)

7. bỏ be

8. were -> was

9. was -> has been 

10. are -> were (vì có yesterday)

11. were -> was (vì cánh cửa số ít)

11.were -> was (vì tiền số ít) 

12. was being -> has been

13. have -> has

14. were -> was

15. will ->  will be

16. were -> was

17. is -> are

18. was -> will be ( vì có next Tuesday => thì tương lai, nhưng là dạng câu bị động)

19. will -> will be

20. is -> was ( vì có yesterday)

21. is -> will be

#Nocopy.

Chúc bạn học tốt.

Xin câu trả lời hay nhất 

By nocoten

^.^

Chắc chắn đúng nha

@Don't worry, the right ones won't leave.

4. Read and correct the mistakes:
1. The letters is sent every day. ⇒ Are
2. My room is cleaned yesterday. ⇒ cleaned up
3. This book was returned tomorrow.⇒ Will return
4. Lunch were being cooked now.⇒ will be cooking
5. The TV were switched off. ⇒ was
6. He is awarded a gold medal yesterday. ⇒ was
7. The parrot is be caught soon.⇒Will
8. My cell phone were blocked yesterday.⇒was
9. My homework was checked now.⇒ is checking
10. The keys are lost yesterday. ⇒ was losted
11. The door were locked soon.⇒was
11. My money were stolen yesterday. ⇒ was
12. The book was being read now. ⇒ is
13. The letter have already been sent.⇒ have been already
14. The baggage were checked at the station. ⇒ was
15. The tickets will bought in two hours. ⇒ buy
16. The window were opened one hour ago. ⇒ Has opened
17. The flowers is being watered now.⇒ water
18. The test was written next Tuesday. ⇒ Will write
19. Berries will gathered by me soon.⇒ gather
20. This dog is drawn by me yesterday.⇒ was drawned
21. The shop is opened next week.⇒ will open

#No coppy

_Nếu thấy hợp lý cho mình xin Câu trả lời hay nhất nha:33_