单项选择题
When a pilot is on board to pilot the vessel the Letter （） must be hoisted．
A.G B.H C.B D.N
单项选择题 Vessels must （） pilot at waiting anchorage．
单项选择题 There shall be two principal （） through the harbor for the passage of vessels of over 60 tons burden．
单项选择题 The transfer procedures for oil products are required to be posted （）.
