21. our teacher gave us !
A.How a good advice B.How good advice
C.What a good advice D.What good advice
22.—Which do you like , tea or coffee ?
— .
A.I like it very much B.Yes , I like coffee
C.Tea , please D.Thank you
23.It was three o’clock we finished the work .
A.where B.by which C.when D.since