21. ---Shall we visit the Shanghai World Expo ______ second time in the vacation?
---Good idea. Some pavilions didn’t open ______ first time we went there.
A. the; the B. a; the C. 不填; the D. a; a
22. Each contestant of the English Talent Competition is allowed 90 seconds to make an introduction to themselves ______.
A. in need B. in addition C. in advance D. in brief