单项选择题
A.for securing a snatch block when snaking cargo into the wings of the hold
B.to prevent cargo from coming in contact with the vessel's frames or shell plating
C.to provide fittings to which cargo lashings may be secured
D.to support the dunnage floors which are laid down between tiers of cargo
单项选择题 Ballast water can only be（）in cargo tanks in exceptional cases where the particular character of the operation of an oil tanker renders it necessary to carry ballast water in excess of the quantity required，provided that such operation of the oil tanker falls under the category of exceptional cases as established by the Organization.
单项选择题 Aboard ship，vertical flat plates running transversely and connecting the vertical keel to the margin plates are called（）.
单项选择题 A vessel having continuous closely spaced transverse strength members is（）.