aboard: 在船(或飞机，车)上。如：I never went aboard a ship.
broad: 为形容词，宽广的。如：He has very broad shoulders.
abroad: 副词，在国外或海外。如：He often goes abroad.
board: 为动词，上(船，飞机，车)。如：The passengers are boarding the plane now.
fee: (进入一个地方，如场馆、学校等)费用
bill: （用餐、电话等）账单
fare: (特指交通等)费用