单项选择题
What can cause a lack of oxygen in a chain locker（）．
A.Absorption B.Osmosis C.Evaporation D.Oxidation
单项选择题 Tonnage openings must be closed by means of（）.
单项选择题 The Vessel’s cargo holds are properly fitted with（）in way of hatches.
单项选择题 The strake on each side of the keel is called a（）.
