第一节 单项填空（共15小题；每小题1分，满分15分）
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
例：It is generally considered unwise to give a child ______ he or she wants．
A．however B．whatever C．whichever D．whenever
答案是B．
21．Have you heard ______ report? People with ______ good knowledge of engineering are in great need in the job market．
A．a；a B．the；a C．a；/ D．the；/
22．Despite the fact that Betty is a lovely girl, she ______ be extremely difficult to work with sometimes．
A．must B．should C．would D．can
