单项选择题
At the magnetic equator there is no induced magnetism in the vertical soft iron because（）.
A.the lines of force cross the equator on a 0°-180°alignment B.the quadrantal error is 0° C.there is no vertical component of the Earth's magnetic field D.the intercardinal headings have less than 1°
单项选择题 A vessel’s position should be plotted using bearings of（）.
单项选择题 A single line of position combined with a dead-reckoning position results in a(n)（）.
单项选择题 A relative bearing is always measured from（）.
