20. I want to have a short talk with you. Could you please spare a few minutes ________?
A. if possible B. if necessary C. if important D. if worthwhile
22. The Browns held _____ they called "family day" once each year.
A. that B. what C. which D. when
23.In some parts of London, missing a bus means __________ for another hour.
A. waiting B. to wait C. wait D. to be waiting
