成绩管理系统,从键盘输入至少10个学生的信息，包括：ID，名字，4门成绩；计算每个学生的总成绩和平均成绩；以ID查询学生的总成绩和平均成绩，并显示；对学生的成绩进行排序并分级，级别为A、B、C......，并显示在屏幕上；插入一个或多个学生成绩，自动排序并显示在屏幕上；删除一个或多个学生成绩；创建学生信息的结构体：-Performance management system, at least 10 students from the keyboard to enter information, including: ID, name, four score　calculate each student' s total score and grade point average　ID query the student' s total score and grade point average, and display　sorting and grading of students'　academic achievement, level A, B, C. ....., and displayed on the screen　insert one or more student achievement, automatically sorted and displayed on the screen　delete one or more student achievement　to create a student information structure: