单项选择题
A.the volume of all intact spaces above the waterline
B.an intact space below the surface of a flooded area
C.an intact space which can be flooded without causing a ship to sink
D.the space at which all the vertical upward forces of buoyancy are considered to be concentrated
单项选择题 In the absence of external forces，the center of buoyancy of an inclined vessel is vertically aligned directly below the（）.
单项选择题 In practice，it is usual for the ship to be loaded（）to improve the vessel’s movement through the water.
单项选择题 If the cause of severe list or trim is off-center ballast，counterflooding into empty tanks will（）.