抽象出教师、学生和后勤人员的公共特性和方法，使用继承定义教师、学生和后勤人员等新类，每个类都又区别于其他类的特殊属性，构造对应的方法分别计算出教师、学生和后勤人员的人数，计算教师、学生和后勤人员的平均年龄-Abstract teachers, students and support staff of public properties and methods defined using the inheritance of teachers, students and support staff and other new classes, each class has special properties different from other classes, methods were constructed to calculate the corresponding teachers, students and the number of support staff, computing teachers, students and support staff, the average age