单项选择题
A. Liquid cargo is loaded and discharged by pumps. B. Liquid cargo is loaded and discharged by tubes. C. Liquid bulk cargo is loaded and discharged by tubes. D. Liquid bulk cargo is loaded and discharged by pumps.
A. The SWL of the derrick is five tons. B. The SWL of the heavy derrick is six tons. C. The SWL of the derrick is six tons. D. The SWL of the crane is six tons.
A. Before leaving the harbour, all derricks must be stowed. B. After leaving the harbour, all derricks must be stowed fore and aft. C. Before leaving the harbour, all derricks must be stowed fore and aft. D. Before leaving the harbour, all heavy derricks must be stowed fore and aft.