单项选择题
The magnetic compass magnets are acted on by the horizontal component of the Earth’s total magnetic force. This magnetic force is GREATEST at the（）.
A.north magnetic pole B.south magnetic pole C.magnetic prime vertical meridian D.magnetic equator
单项选择题 The lubber’s line on a magnetic compass indicates（）.
单项选择题 The lubber’s line of a magnetic compass（）.
单项选择题 The horizontal angle between the magnetic meridian and the north-south line of the magnetic compass is（）.
