post- office box邮政信箱
post-office E box邮政信箱
The Headmaster's Post-office Box校长的信箱
同义词：PO BoxPOBcall boxletter box
N-COUNT（可数名词） A post office box is a numbered box in a post office where a person's mail is kept for them until they come to collect it. 邮政信箱