21. ---Have you heard the latest news? ---No, What ________?
   A. is it          B. is there            C. are they        D. are those
22. Some pre-school children go to a day care center, __________ they learn simple games and songs.
   A. then          B. there              C. while         D. where
23. The manager suggested an earlier date ____________ the meeting.
   A. on           B. for              C. about            D. with
24. ---It’s a long time since I saw my sister. ---_______________ her this weekend?
   A. Why not visit                   B. why not to visit 
   C. Why not visiting                 D. Why don’t visit