单项选择题
A.cubic meters
B.both cubic meters and cubic feet
C.both kilos and pounds
D.barrels of 55 gallon capacity
单项选择题 You are crossing a narrow channel in a 15-meter vessel when you sight a tanker off your port bow coming up the channel. Which statement is TRUE? （）
单项选择题 You are cleaning the tanks after carrying a cargo of crude oil. Which statement is TRUE? （）.
单项选择题 While underway and towing an unmanned tank barge you are required to（）.