单项选择题
A.total number of observations B.average wind force on the Beaufort scale C.average wind force in knots D.percentage of calms
The maximum difference between mean time and apparent t...
单项选择题The maximum difference between mean time and apparent time is （）.
A.equal to the longitude expressed in time units B.about 16 minutes C.the difference between the GHA of mean sun and the first point of Aries D.15°of arc
The description Racon beside an illustration on a chart...
单项选择题The description Racon beside an illustration on a chart would mean a （）.
A.radar conspicuous beacon B.circular radiobeacon C.radar transponder beacon D.radar calibration beacon
The compass rose on a nautical chart indicates both var...
单项选择题The compass rose on a nautical chart indicates both variation and （）.
A.deviation B.annual rate of variation change C.precession D.compass error
