Introduction - If you have any usage issues, please Google them yourself
" 1. Enter list" 输入记录
" 2. Delete a record from list" 从表中删除记录
" 3. print list " 显示链表中所有记录
" 4. Search record on name" 按照姓名查找记录
" 5. Save the file" 将链表中记录保存到文件中
" 6. Load the file" 从文件中读入记录
" 7. compute the score" 计算所有学生的总分和均分
" 8. insert record to list " 插入记录到表中
" 9. Quit" 退出