二单项选择
( )21. He arrived____ London ____ a cold winter night.
A at; at B. in; on C. in; in D. \; on
( )22. ______ hard work it is!
A. What a B. How a C. What D. How
( )23. --Nice to meet you! I ______ you for a long time.
--I ________ in Beijing last month. I’ve just come back.
A.haven’t seen, am B.didn’t see, am
C.haven’t seen, was D,didn’t see, was
