对学生成绩管理系统要求完成如下功能：

(1)插入学生成绩信息

(2)输出学生每门课程平均分

(3)输出个人平均分超过90分学生的信息

(4)对任意一门学科成绩进行排序

(5)退出

-Student achievement management system requirements for the following functions:

(1) into the student achievement information

(2) Output average student per course

(3) The output score more than 90 points the average individual student information

(4) For any one discipline to sort the results

(5) Exit