说明：  一个教师类Teacher，用于学校每个系统的管理软件。系统在管理教师时，所管理的信息主要有教师的编号，姓名，性别，年龄，家庭住址，电话号码等，于是抽取这些属性来描述“教师”这个实体。
(Category of a teacher Teacher, for each school system management software. System in the management of teachers, the management of information teachers have the main number, name, sex, age, home address, telephone number, etc., so taking these attributes to describe the )