单项选择题
While underway and towing an unmanned tank barge you are required to（）.
A.maintain a strict watch on the barge from the towing vessel B.fly a red flag from the towing vessel C.open the tops of all empty tanks on the barge D.take hourly soundings of any loaded tanks on the barge
单项选择题 While testing a cargo tank，your oxygen indicator reads 25% oxygen in the tank. You would then （）.
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? （）
