1. The homework must (submit) by tomorrow.

2. The floor must (clean) before the guests arrive.

3. All documents must (sign) before sending.

4. The windows must (close) at night.

5. The messages must (reply) within 24 hours.

6. The homework should (check) by the teacher.

7. The plants should (water) every morning.

8. The floors should (sweep) after the lesson.

9. The instructions should (follow) carefully.

10. The tests should (review) before submission.

11. The classroom should (arrange) before the lesson starts.

12. The homework can (submit) online.

13. The documents can (sign) digitally.

14. The windows can (open) for fresh air.

15. The results could (check) tomorrow.

16. The samples could (analyze) in the lab.

17. The meeting may (postpone) due to rain.

18. The letters may (send) later today.

19. The students might (inform) about the change.

20. The packages might (deliver) tomorrow.

21. The instructions may (explain) again.

22. The homework has to (finish) by 6 p.m.

23. The emails have to (check) before sending.

24. The windows have to (close) at night.

25. The packages have to (deliver) today.

26. The reports have to (submit) before Friday.

27. The homework ought to (submit) today.

28. The emails need to (send) as soon as possible.

29. The plants need to (water) twice a day.

30. The tests ought to (review) before the lesson.

31. The reports ought to (finish) before Friday.

32. The instructions need to (explain) clearly.

33. The packages need to (deliver) immediately.

34. The students must submit their homework by tomorrow.
⟶ The homework .

35. The janitor should clean the classroom before the guests arrive.
⟶ The classroom .

36. The librarian ought to return the books before the end of the week.
⟶ The books .

37. The IT staff have to check all the computers before the meeting.
⟶ All the computers .

38. The city workers have to fix the traffic lights by the end of the day.
⟶ The traffic lights .

39. The students ought to clean the blackboard before leaving.
⟶ The blackboard .

40. The volunteers may organize the charity event next week.
⟶ The charity event .