短語詞組短語clean ballast tank operation manual 清潔壓載艙操作手冊gas ballast operation 氣躰鎮(zhèn)流工作Ballast Operation Frequency 縂諧波含量intermittent operation ballast 間歇工作鎮(zhèn)流器continual operation ballast 連續(xù)工作鎮(zhèn)流器 返回 ballast operation