学生成绩管理是学校教务管理的重要组成部分，其处理信息量很大，本实验是对学生的成绩管理作一个

简单的模拟，用菜单选择操作方式完成下列功能：

（1）学生成绩；

（2）查询学生成绩；

（3）插入学生成绩；

（4）删除学生成绩-School student achievement management is an important part of educational administration and its handling a large amount of information, the students of this experiment is a simple performance management for simulation, with a menu to select the operation to complete the following functions: (1) student achievement　(2 ) query student achievement　(3) into the student achievement　(4) Delete student achievement