21. I woke up with bad headache, yet by evening the pain had gone.
A. the; the B. the; an C. a; the D. a; an
22. Jack is a great talker. It’s high time that he something instead of just talking.
A. will do B. has done C. do D. did
23. --- What does the sign over there say?
---No person _________ bring drinks into the student computer pool.
A. will B. may C. shall D. must
