单项选择题
A. Containers are loaded and discharged by gantry cranes. B. Cases are loaded and discharged by gantry cranes. C. Cases are loaded and discharged by heavy derricks. D. Containers are loaded and discharged by heavy derricks.
液体散货用泵装卸的。（）A. Liquid cargo is loaded and discharged by...
单项选择题液体散货用泵装卸的。（）
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.
这个吊杆的安全工作负荷是6吨。（）A. The SWL of the derrick is five tons...
单项选择题这个吊杆的安全工作负荷是6吨。（）
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.
船舶离港之前，所有的吊杆必须纵向收放好。（）A. Before leaving the harbour, al...
单项选择题船舶离港之前，所有的吊杆必须纵向收放好。（）
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.
