继承与多态性生成表示学生的类XS,提供成员函数dispXM()、dispXB()和dispNL()分别用来显示姓名、性别和年龄,并将他们全部定义为纯虚函数 生成CZS类表示初中生,包含数据成员xm、xb和nl表示学生的姓名、性别和年龄-Generated, said the students in the class XS, the member function dispXM (), the dispXB () and dispNL () are used to display the name, gender and age, and all of them defined as a pure virtual function　generate a junior high school the CZS class said, contains datamembers xm, xb, and nl expressed the student s name, gender and age