单项选择题 Longitudinal and transverse separtions between the tanks,which are used to prevent liquids from leaking from one double bottom tank into the other ,are called（）.

单项选择题 （）provides strength and strong space for fule,lubricating oil,fresh water,salt(ballast)water and potable water.

单项选择题 The formost and aftermost spaces of the vessel are the（）.