A.Remove deviation on the intercardinal headingsB.Remov……

单项选择题The MOST important feature of the material used for making the binnacle of a standard magnetic compass is that it is（）.

A.nonmagnetic
B.weatherproof
C.corrosion resistant
D.capable of being permanently affixed to the vessel

单项选择题The most accurate method of determining gyrocompass error while underway is by（）.

A.Comparing the gyro azimuth of a celestial body with the computed azimuth of the body
B.Comparing the gyro heading with the magnetic compass heading
C.Determining from the chart the course made good between celestial fixes
D.It cannot be determined accurately at sea due to drift of unknown currents

单项选择题The magnetism in the various structures of a ship changing as a result of cruising，vibration，or aging is termed（）.

A.permanent magnetism
B.subpermanent magnetism
C.induced magnetism
D.variable magnetism

单项选择题The line which connects the points of zero magnetic dip is（）.

A.An agonic line
B.The magnetic equator
C.A magnetic meridian
D.All of the above

单项选择题The Flinders bar and the quadrantal spheres should be tested for permanent magnetism at what interval（）.

A.They are not subject to permanent magnetism; no check is necessary
B.Semiannually
C.Annually
D.Every five years