习惯用语be in ballast1.只装 压船物而没装货; 压舱航行2.[喻]沉着, (为人)可靠have no ballast1.不镇定, 不沉着mental ballast1.心理[性格]上的稳定性特殊用法bottom ballast1.底碴boxed-in ballast1.轨枕间道碴crushed stone ballast1.碎石道碴foul ballast1.泥污碴床high-tension mercury lamp ballast1.高压水银灯镇流器incrusted ballast1.混碴lead ballast1.铅压载low-power-factor mercury lamp ballast1.低功率因数水银灯镇流器pit-run gravel ballast1.坑砾道碴, 未筛砾石道碴rear-wheel ballast1.后轮配重solid ballast1.固体压载variable ballast1.可变压载water ballast1.【船】水压载