[单选] Although goods have been lost or damaged whilst in the custody of the Shipowner，（）not necessarily responsible，for his liability in respect of them may have been excluded by the rules of common law or by the express terms of the contract or by statute.

If the pump for a hydraulic anchor windlass is overheating, the cause may be （）. excessive drive motor speed。 excessive pump discharge pressure。 too low of a tilting box angle。 insufficient drive motor speed。 输送聚合物母液，选择螺杆泵，其主要原因是（） 螺杆泵工作平稳。 有自吸能力。 成本较低。 防止粘度损失。 依据《安全生产违法行为行政处罚办法》的规定，违法事实确凿并有法定依据，安全生产行政执法人员可以当场作出对个人处以一百元以下罚款的行政处罚决定。 通常使用盐酸来溶解铁化合物。但是，使用时必须投加（）以防管道腐蚀。 缓蚀剂。 杀菌剂。 阻垢剂。 破乳剂。 Refrigerant enters the condenser as a （）. high pressure liquid。 low pressure vapor。 high pressure vapor。 low pressure liquid。 Although goods have been lost or damaged whilst in the custody of the Shipowner，（）not necessarily responsible，for his liability in respect of them may have been excluded by the rules of common law or by the express terms of the contract or by statute.