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.
A. The ship needs loading. B. The ship needs discharging. C. The ship needs unloading. D. The ship needs loading and discharging.
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?