（1）信息维护：
要求：学生信息数据要以文件的形式保存，能实现学生信息数据的维护。此模块包括子模块有：增加学生信息、删除学生信息、修改学生信息
（2）信息查询：
要求：查询时可实现按姓名查询、按学号查询
（3）成绩统计：
要求：A输入任意的一个课程名（如数学）和一个分数段（如60--70），统计出在此分数段的学生情况。
（4）排序：能对用户指定的任意课程名，按成绩升序或降序排列学生数据并显示排序结果（使用表格的形式显示排序后的输出结果）((1) Information maintenance:
Requirements: Student information data should be saved in the form of documents, which can realize the maintenance of student information data. This module includes sub-modules: adding student information, deleting student information, modifying student information.
(2) Information inquiry:
Requirements: When inquiring, it can be queried by name and school number.
(3) Achievement statistics:
Requirements: A input any course name (e.g. mathematics) and a fraction (e.g. 60-70), statistics of students in this fraction.
(4) Sorting: Students'data can be arranged in ascending or descending order according to any course name designated by users and the sorted results can be displayed (the output of the sorted results can be displayed in tabular form).)