单项选择题
The purpose of inert gas systems aboard tank vessels is to（）.
A.allow sufficient oxygen in the tank to sustain life B.prevent outside air from entering the tank C.provide increase in cargo discharge pressure D.comply with double hull pollution prevention regulations
单项选择题 The primary objective of a Ro-Ro vessel is to（）.
单项选择题 The piping that routes an oil cargo from the manifold to underdeck pipelines is known as a （）.
单项选择题 The permanent magnetism of a vessel may change in strength due to（）.
