单项选择题
很多船上在每个舱口处都有两个吊杆及两台起货机。（）
A. Many ships have two derricks at each hatch. B. Many ships have two winches at each hatch. C. Many ships have two derricks and two winches at each hatch. D. Many ships have two derricks and two winches at each hatch cover.
单项选择题 重吊杆用于吊大的重件。（）
单项选择题 船舶需要装卸货。（）
单项选择题 水手长，我们为什么要开舱盖?（）
