有多个学生、多门课程，可以求全班单科的平均分、某个人的多门课的平均分，其它功能自定。根据实际需求，我额外设计了查询、显示学生成绩，插入、删除学生记录和排序等功能。-There are a number of students, more courses, you can seek Billing Division of the average in his class, a class of individuals more than the average score, and other c