单项选择题
A.positive stability
B.negative stability
C.neutral stability
D.maximum stability
单项选择题 In small angle stability，the metacentric height（）.
单项选择题 In small-angle stability，when external forces exist，the buoyant force is assumed to act vertically upwards through the center of buoyancy and through the（）.
单项选择题 In the presence of external forces，the center of buoyancy of an inclined vessel is vertically aligned with the（）.