1. 设计一个大学的类系统，学校有学生、教师、职员、每种人员都有自己的特性，他们之间又有相同的地方。利用继承机制定义这个系统中的各个类及类上必须的操作-(1) designing a college class system, schools, students, teachers, staff, each staff has its own characteristics, they have the same place. Inheritance mechanism to define ea