单项选择题
A ship lists and trims about the（）.
A.center of gravity B.center of buoyancy C.center of flotation D.centroid of the underwater volume
单项选择题 A ship is inclined at an angle of loll. In the absence of external forces，the righting arm (GZ) is（）.
单项选择题 A partially full tank causes a virtual rise in the height of the（）.
单项选择题 A neutral equilibrium position for a vessel means that the metacenter is（）.
