单项选择题
A.nonmagnetic B.weatherproof C.corrosion resistant D.capable of being permanently affixed to the vessel
The magnetic compass operates on the principle that（）.A...
单项选择题The magnetic compass operates on the principle that（）.
A.like magnetic poles attract B.unlike magnetic poles repel C.unlike poles attract D.the poles of the compass line up with the geographic poles of the earth
The magnetic compass magnets are acted on by the horizo...
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
The lubber’s line on a magnetic compass indicates（）.A.c...
单项选择题The lubber’s line on a magnetic compass indicates（）.
A.compass north B.the direction of the vessel's head C.magnetic north D.a relative bearing taken with an azimuth circle
