单项选择题
A.Whenever its serviceability is in doubt
B.In accordance with the manufacturer's recommendation
C.At least once a month
D.All of the above
单项选择题 When inspecting a tank barge to see that it has all the required fire extinguishers and other safety items aboard，which of the following is the best source for determining what is required? （）
单项选择题 When backing down with sternway，the pivot point of a vessel is（）.
单项选择题 What will NOT be found on the Certificate of Inspection of an ocean going tanker?（）