1.　　手动录入
2.　　计算每门课程的总分和平均分
3.　　按学生总分由高到低排出名次表
4.　　按学号由小到大排出成绩表
5.　　按姓名查询学生排名及其考试成绩
6.　　统计
7.　　输出
0 .　退出系统(1. manual input
2. calculate the total and average scores of each course
3. according to the total score of students from high to low row list
4. according to student achievement table from discharge
5., according to the name of the student rankings and their examination results
6. statistics
7. output
0. quit the system
Please select and enter the corresponding menu item:
Then operate accordingly according to the options entered by the user.)