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.
这组词都有“手杖”的意思,其区别是:
staff: 多指走路爬山时用作支持或防卫使用的长木棒。
stick: 普通用词,指木制的细长手杖。
cane: 多指用藤或竹制成的细长的手杖。