单项选择题
A.variation B.true directions C.magnetic directions D.annual rate of variation change
Which chart symbol indicates the bottom is clay（）.A.Cly...
单项选择题Which chart symbol indicates the bottom is clay（）.
A.Cly B.Cla C.Cl D.C
Where would you obtain data on currents for areas of th...
单项选择题Where would you obtain data on currents for areas of the world not covered by the National Ocean Service（）.
A.In the Coast Pilot B.In the Nautical Almanac C.In the List of Lights D.In the Sailing Directions
The soundings on the imperial chart are measured in（）.A...
单项选择题The soundings on the imperial chart are measured in（）.
A.Feet B.Yards C.Fathoms D.Meters
