单项选择题
A.Danger of heavy ship sweat exists; constant and vigorous ventilation is required
B.There is danger of heavy cargo sweat if outside air is introduced by ventilation
C.There is little danger of ships sweat, slight possibility of cargo sweat; moderate ventilation is needed
D.The po sibility of any sweat problem, either cargo or ship, is frame
单项选择题 0n a vessel, the keel is the primary strength member of the lower hull form in which direction?（）.
单项选择题 0n the fully containerized ship, approximately one-third or more of the cargo is on deck above the rolling center. Top stowed containers are subject to（）.
单项选择题 0ne function of a hulwark is to（）.