单项选择题
Stability is determined by the relationship of the center of gravity and the（）.
A.water depth B.keel C.center of flotation D.center of buoyancy
单项选择题 Repair of vital machinery and services on a ship should be accomplished（）.
单项选择题 Initial stability refers to stability（）.
单项选择题 Initial stability of a vessel may be improved by（）.
