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。-There are two disk file " A" and " B" , the stored line of letters, requested the information in these two documents combined (in alphabetical order), output to a new file