ballooning

n.热气球飞行运动

balky, ball, ball game, ball-bearing, ball-point, ball-point pen, ballad, ballade, ballast, ballboy, ballgirl, ballcock, ballerina, ballet, ballet-dancer, ballistic missile, ballistics, ballocks, ballocks (also bollocks), balloon, balloon-borne, balloonist, ballot, ballot-box, ballpark, ballroom, balls-up, bally, ballyhoo, balm, balmily, balminess, balmy, baloney, balsa, balsam, Baltic, baluster, balustrade, bamboo, bamboo-shoot,