A ——air mail B —— date stamp C —— Express Mail Service (EMS) D—— express delivery letter E —— letter box F —— please forward G —— post-office box H ——registered letter I ——sub-post office J —— telecommunications service K —— regular mail L—— mail order M —— mailing list N ——postage stamp O —— post-free P ——postage paid ( ) 特快专递 ( )面付邮资