单项选择题
A. Heavy derrick is used for lifting large heavy cargo. B. Derrick is used for lifting large heavy cargo. C. Heavy derrick is used for lifting dry bulk cargo. D. Derrick is used for lifting dry bulk cargo.
船舶需要装卸货。（）A. The ship needs loading.B. The ship needs d...
单项选择题船舶需要装卸货。（）
A. The ship needs loading. B. The ship needs discharging. C. The ship needs unloading. D. The ship needs loading and discharging.
水手长，我们为什么要开舱盖?（）A. Bosun, why do we open hatch covers?B...
单项选择题水手长，我们为什么要开舱盖?（）
A. Bosun, why do we open hatch covers? B. Officer, why do we open hatch covers? C. Bosun, why do we close hatch covers? D. Bosun, why do we open hatches?
操作完后，关掉电动机。（）A. After operation, start the electric mot...
单项选择题操作完后，关掉电动机。（）
A. After operation, start the electric motor. B. Before operation, stop the electric motor. C. Before operation, start the electric motor. D. After operation, stop the electric motor.
