14. I don't stay up late any more.
→I used to stay up late
15. The students are cleaning the classrooms.
→The classrooms are being cleaned by the students
18. "Why don't we visit the museum after lunch?", he said
→He suggested visiting the museum after lunch
19. They should finish their work soon. (passive voice)
→ Their work should be finished soon
20. Ba said,"Why don't we stop eating chicken to avoid being infected with bird flu.?"
→Basuggested that chicken shouldn't be eaten so that they could avoid being infected with bird flu
21. The last time she went out with him was 9 months ago.
→It is 9 months since she last went out with him
14. I don't stay up late any more.
→I used to....stay up late ...
15. The students are cleaning the classrooms.
→The classrooms...are being cleaned by the students...
18. "Why don't we visit the museum after lunch?", he said
→He suggested...visiting the museum after lunch..
19. They should finish their work soon. (passive voice)
→...Their work should be finished soon....
20. Ba said,"Why don't we stop eating chicken to avoid being infected with bird flu.?"
→Basuggested that chicken shouldn't.....be eaten to avoid being infected with bird flu ......
21. The last time she went out with him was 9 months ago.
→It was 9 months since she last went out with him.