价格歧视（Price discrimination）
参考答案：
价格歧视是指这样一种做法，出售同一种商品，厂商向一个买者索取的价格高于其他的买者。
—Mary, could you tell me if your mother ________ our school sports meeting tomorrow?
—I think she will come to school if she ________ free. [ ]
A. will take part in; will be
B. takes part in; is
C. will take part in; is
D. takes part in; will be
关于海南各市县的别称，以下说法正确的是_____。
A．五指山市是“全国民闻艺术之乡”
B．琼海市是“槟榔之乡”
C．昌江县是“芒果之乡”
D．海口市是“棒子之多”
