说明：  随机文件读写，实现了从文本中读取个人资料，成绩等信息，并可以追加记录。运行时需要先创建一个文本文件，并修改读取路径。
(Random file read and write, realize from reading the text of personal information, results and other information and would provide an additional record. Run-time need to create a text file, and modify the path to read.)