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。
21. Most construction workers can earn over two thousand RMB ____ month
but usually they get their wages by______ year.
A. the , the B. the ; the C. a ; the D. a ; a
22.—John, what about going for a bicycle ride tomorrow?
—______. I am looking forward to it．
A．Sounds fantastic B．That’s all right C．No kidding D．Up to you．
23. As we all know , bad eating habits and a of exercise may lead to health problems .
A. limit B. lack C. need D. demand
