单项选择题
While testing a cargo tank，your oxygen indicator reads 25% oxygen in the tank. You would then （）.
A.enter the tank safely B.suspect the accuracy of the reading C.ventilate the tank D.test for nitrogen
单项选择题 Which vessel in ocean service is not subject to Annex V of MARPOL 73/78? （）
单项选择题 Which substance is NOT considered to be Oil under the pollution prevention regulations? （）
单项选择题 Which step is NOT generally taken when gas-freeing a tank?（）.
