underbuyvt.优惠价买underprep.低于；在 ... 下；在 ... 内；在 ... 控制下adv.在昏迷中；在 ... 下adj.下面的；从属的；少于的underhand polish人工研磨under heavy debt债台高筑underhang lining吊框支柱underhand stopes俯采工作面under one's feetunder an embargo属禁运之列underlying layer下卧层underlying scale隐伏尺度undercarriage up起落架已收起underrunner mill下旋式碾磨