单项选择题
A.an officer's license B.an officer's promotion C.an officer's statement D.a seaman's book
In a weather report “GMT” stands for（）.A.Greenwich Mean...
单项选择题In a weather report “GMT” stands for（）.
A.Greenwich Mean Time B.Gross Mean Time C.Great Mean Time D.Gross Metric Ton
It is danger for vessels without the use of（）to approac...
单项选择题It is danger for vessels without the use of（）to approach the estuary in such poor visibility.
A.Loran C B.Direction Finder C.Gyro- compass D.Radar
When visibility is 20 nautical miles, we say that visib...
单项选择题When visibility is 20 nautical miles, we say that visibility is（）.
A.very good B.good C.poor D.moderate
