实现学生成绩的读入（从键盘读入和从文件读入）、查询（按学好查询和按姓名查询）、更新（修改、删除、插入）、排序、统计、显示、存盘等。-To achieve student performance in reading (from the keyboard and read from a file), check (by master query and query by name), update (modify, delete, insert), sorting, statistics, dis