21.——What do you think of ________ lecture given by Professor Thomas?
——Great. I quite agree to his idea that every one can make ______ difference to society.
A. the, a B. a, a C. the, the D. a, the
22.——They say that my new car is a ____________ of money.
——Don’t you think those words are just sour grapes?
A. lack B. waste C. question D. load
