单项选择题
A.compass north and magnetic north B.compass north and true north C.magnetic meridian and the geographic meridian D.your vessel's heading and the magnetic meridian
Variation is a compass error that you（）.A.can correct b...
单项选择题Variation is a compass error that you（）.
A.can correct by adjusting the compass card B.can correct by adjusting the compensating magnets C.can correct by changing the vessel's heading D.cannot correct
Variation in a compass is caused by（）.A.worn gears in t...
单项选择题Variation in a compass is caused by（）.
A.worn gears in the compass housing B.magnetism from the earth's magnetic field C.magnetism within the vessel D.lack of oil in the compass bearings
True heading differs from magnetic heading by（）.A.devia...
单项选择题True heading differs from magnetic heading by（）.
A.deviation B.variation C.compass error D.northerly error
