单项选择题
（）refers to the angle between true north and the heading line of the ship.
A.True position B.True meridian C.True course D.True bearing
单项选择题 （）tankers over 100 meters long must not proceed beyond Dongbei buoy.
单项选择题 （）the canal transit, the radar was operating.
单项选择题 （）the morning from 0800 to 1200 chief officer is on duty.
