ballast

n.压舱物

balcony, bald, bald eagle, balderdash, balding, baldly, baldness, bale, baleful, balefully, balk, balk (also baulk), balky, ball, ball game, ball-bearing, ball-point, ball-point pen, ballad, ballade, ballboy, ballgirl, ballcock, ballerina, ballet, ballet-dancer, ballistic missile, ballistics, ballocks, ballocks (also bollocks), balloon, balloon-borne, ballooning, balloonist, ballot, ballot-box, ballpark, ballroom, balls-up, bally, ballyhoo,