(   ) 21 ---How long __________ your parents ___________?
       ---For about twenty years.
       A did, marry  B have, married      C have, got married    D have, been married
(   ) 22 Mr Chen is over 80, ________ he still looks healthy.
       A and               B or           C but              D for
(   ) 23 ---Look at the boy running on the playground. Is it Davis?
       ---It ______ be him. I saw him go to the teachers’ office just now.
       A mustn’t           B can’t           C couldn’t         D must
(   ) 24 My uncle ___________ a farmer. Now he is a driver.
       A is used to          B is used to be        C used to being   D used to be
(   ) 25 There is little coffee in the bottle,____________?
       A is there           B isn’t there          C is it           D isn’t it