21．Playing basketball is _____great fun; it also provides us with a chance to develop our sense of ______team spirit.
A．a;/ B．/; a C. a; the D. /；/
22. Obviously, this anti-smoking _____ is mainly aimed at teenagers.
A. campaign B. war C. battle D. fighting
23．When _______ comes to super stars, young teenagers come to life easily.
A. that B. this C. it D. one
