说明：  实现一个简单的学生宿舍管理系统。要求能添加、更新和删除和查询学生信息的功能，每条记录应该有：学号、姓名、宿舍号码、所在系、年级。
(Realize a simple student hostel management system. Request to add, update, and delete student information and query functions, each record should have: Student ID, name, number of quarters, where the line, grade.)