16£® Mrs. Green went to Shanghai last week. She will be back _____five days. 

A.   at          B. after          C. on              D. in

17.  I hope your dream will _______.

A. come true      B. come out      C.  come in        D. come on

18.   --  ______ does your school have a sports meeting?       --Twice a year.

A.     How far        B. How long      C. How often       D. How soon

  19.  While Betty __________ a bike , she met Lily.

      A. was rideing      B. was riding     C. rode            D. riding

20.  I was             to see the police at my home yesterday.

A. surprised           B. surprising      C. interesting      D. boring

21. ---My bag is         style. ---Maybe you should buy a new one.

A. out of           B. out for                     C. out from       D. outside