单项选择题
In plotting a running fix，how many fixed objects are needed to take your lines of position from? （）
A.Three B.Two C.One D.None
单项选择题 At the magnetic equator there is no induced magnetism in the vertical soft iron because（）.
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)（）.
