1. The homework (complete) by the students before the class started.

2. The room (decorate) before the party began.

3. The window (fix) by the janitor before the principal arrived.

4. The plants (water) before the morning assembly.

5. The food (prepare) before the guests sat down.

6. The books (return) to the library before the librarian checked the shelves.

7. The floors (clean) before the teachers entered the classroom.

8. The clothes (fold) by my sister before our parents came home.

9. The posters (hang) on the walls before the visitors arrived.

10. The car (wash) before my father used it.

11. The lesson (explain) before the students did the exercises.

12. The report (submit) before the manager left the office.

13. The table (set) for breakfast before we went downstairs.

14. The letters (send) before the postman arrived.

15. The floor (sweep) before the guests entered.

16. The homework (check) before the bell rang.

17. The lamp (repair) before the night guard began his shift.

18. The chairs (arrange) before the meeting started.

19. The picture (frame) before the exhibition opened.

20. The dishes (wash) before dinner was served.

21. The conference hall (prepare) before the delegates arrived.

22. The software (update) before the training session.

23. The emails (reply) before the manager checked his inbox.

24. The packages (deliver) before the courier left the building.

25. The new equipment (install) before the experiment started.

26. The garden (plant) before the school festival.

27. The experiment (conduct) before the professor arrived.

28. The new policies (announce) before the staff meeting.

29. The audio system (check) before the concert.

30. The windows (paint) before the winter came.

31. The documents (translate) into multiple languages before the conference started.

32. The proposal (evaluate) by the board before the announcement.

33. The website (design) before the marketing campaign launched.

34. The contracts (negotiate) before signing the final deal.

35. The paintings (restore) by experts before the exhibition opened.

36. The research data (compile) before the publication.

37. The teacher had explained the lesson before the students asked questions.
⟶ The lesson .

38. The workers had repaired the road before the festival.
⟶ The road .

39. The chef had prepared the dishes before the guests arrived.
⟶ The dishes .

40. They had organized the conference before the delegates arrived.
⟶ The conference .

41. The librarian had arranged the books before the library opened.
⟶ The books .

42. The students had completed the project before the deadline.
⟶ The project .

43. The committee had approved the new rules before the meeting.
⟶ The new rules .

44. The team had finished the research before the supervisor checked it.
⟶ The research .

45. The staff had decorated the hall before the guests arrived.
⟶ The hall .

46. The manager had signed the contracts before the meeting began.
⟶ The contracts .

47. The students had completed the survey before the teacher collected it.
⟶ The survey .

48. The secretary had typed all the reports before the manager came.
⟶ All the reports .

49. The engineer had repaired the machines before production resumed.
⟶ The machines .

50. The assistants had prepared the laboratory before the experiment started.
⟶ The laboratory .