第4题:[单选题] When a pushing vessel and a vessel being pushed are rigidly connected in a composite unit, they shall be regarded as ______ . A. a tugboat B. a sailing vessel C. a power-driven vessel D. a vessel propelled by machinery and under sail 参考答案:C 【参考译文】当一艘顶推船与一艘被顶推船几乎成一整体时,它们应被看成一艘机动船。 【解 析】pushing vessel顶推船vessel being pushed被顶推船 composite unit 整体