21．—Oh no! I put my bag down here，but now it’s gone.
—______________．Shall I call the police?
A．Excuse me B．Oh，dear C．No problem D．OK
22．I wasn’t sure whether I had come to_____________ right office. There was no name on________________ door．
A．a；不填 B．the；a C．a；the D．the；the
