学生成绩管理系统的功能如下：

1.定义及输出。可以显示系统内所有学生的成绩情况；

2.计算并排序。可以计算每个学生三门课程的总分（sum，单精度）及平均分（aver，单精度，并输出一位小数），同时也可以对所有学生的总分情况进行一个由高到低的排名；

3.查找。任意输入一位学生的姓名，打印出他的所有数据。并且能多次查找。

4.统计。统计输出不及格的学生名单和对应的课程。

5.退出成绩管理系统。

-Student achievement management system functions as follows: 1 Definitions and output. The system can display the results of all students　(2) is calculated and sorted. Three courses each student can calculate the total score (sum, single precision) and the average (aver, single precision, and output a decimal), but can also score for all students to conduct high to low ranking　3 search. Enter the name of any student, print out all of his data. And can many times find. 4 Statistics. Statistics do not pass the output list of students and corresponding courses. 5 out of performance management system.