3．句型转换

20.She _____________(play) the guitar while her sister_______________(sing).

19. She told me she _________________(be) to Sanya three times.

18. I ______________(be) to Shanghai before.

17. He said he _____________already_________(give) the book to the teacher.

16. He ______________(not tell) you the news yet.

15.She ____________(not go) to Qingdao because she ________________ (go) there before.

14. We were surprised at what she ________already ______(do)

13. I waited until he _______________(finish) his homework.

12..We _______________(learn) about 4000 English words by the end of last term.