题目：有两个磁盘文件A和B,各存放一行字母，要求把这两个文件中的信息合并（按字母顺序排列）， 　　　 输出到一个新文件C中。-topic : There are two disk files A and B, the store his letter, the requirements of these two documents, the information merger (in alphabetical order), the output to a new file C.