单项选择题
A.increase their strength
B.provide drainage from the decks
C.relieve deck stress
D.All of the above
单项选择题 As the displacement of a vessel increases，the detrimental effect of free surface（）.
单项选择题 An unstable upright equilibrium position on a vessel means that the metacenter is（）.
单项选择题 Aboard a vessel，multiplying a load’s weight by the distance of the load’s center of gravity from the centerline results in the load’s（）.