短語(yǔ)詞組短語(yǔ)valve level fall -off 閥桿脫落low water level cut -off device 低水位?，ぱb置SLTO Sea -Level Take-Off 海平面起飛pressure level -off 壓力趨于穩(wěn)定level -off degree polymerization 分布均勻的聚合度automatic level -off 自動(dòng)調(diào)平 返回 level-off