I\'m trying to tweak the dired-find-file function in emacs on Windows XP so that when I open (say) a pdf file from dired it fires up a copy of Acrobat Reader and opens that file with it, instead of op
目录什么是集合?集合与列表的区别集合的创建方法集合的增删改add函数update函数remove函数clear函数del方法删除集合关于集合的重要说明获取两个集合交、并、差集的函数difference()函数intersection()函数union()函