21. Who is the man ______ a blue shirt? I have never seen him before.
 A. is wearing               B. dressed up           C. dressed in            D. worn 
22. _______ once before, after your class I got my visa(签证). So thank you again.
 A. Having rejected         B. Rejected            C. Being rejected      D. To be rejected 
23. The police will have to         the room for fingerprints. 
 A. check                   B. examine           C. clean               D. analyze