21. ______ great number of people watched ______ opening ceremony of the 30th Olympic Games in London.
A. A; the B.The; a C. A; a D. The; the
22. It is not what you are dreaming of but what you are doing _____ matters.
A. which B. it C. that D. this
23. —Shall I practice Ping pong and volleyball together? I’m crazy about ball games.
—No, I’d rather you ________ on one at a time.
A. should focus B. focused C. would focus D. focus
