单项选择题
Deviation is the angle between the（）.
A.true meridian and the axis of the compass card B.true meridian and the magnetic meridian C.magnetic meridian and the axis of the compass card D.axis of the compass card and the degaussing meridian
单项选择题 Deviation in a compass is caused by the（）.
单项选择题 Compass error is equal to the（）.
单项选择题 Compass deviation is caused by（）.
