学生管理系统，包括添加学生信息，排序（按姓名、学号、成绩、平均分等），删除（按姓名、学号），按姓名、学号查找，显示学生信息-Student management system, including the addition of student information, sorting (by name, school, grades, grading on average), delete (by name, student number), by name, student number s