单项选择题
A lightship is like an/a（）(普通船舶).
A. ordinary vessel B. common ship C. common vessel D. cargo ship
单项选择题 A container ship is one of the （）(干货) ships .
单项选择题 Some ships have（）(特殊职责) ,such as tugs.
单项选择题 （）（货船）can be divided into two basic types.
