单项选择题
The horizontal angle between the magnetic meridian and the north-south line of the magnetic compass is（）.
A.deviation B.variation C.compass error D.dip
单项选择题 The gyrocompass error resulting from your vessel’s movement in OTHER than an east-west direction is called（）.
单项选择题 The greatest directive force is exerted on the magnetic compass when the（）.
单项选择题 The Flinders bar on a magnetic compass compensates for the（）.
