程序采用子程序的结构形式，子程序有：将输入的二位月份数转换为二进制数的子程序；从字符表中查找相应的英文缩写的子程序；将月份的英文字母显示在屏幕上的子程序。-Program structure using subroutines, subroutine are: the input of two months as a binary number conversion routines from the character table to find the appropriate abbrev