Which magnetic compass corrector（s）CANNOT be set on a heading of magnetic east or magnetic west（）.

单项选择题Which magnetic compass corrector（s）can be set while the vessel is on a heading of magnetic north or magnetic south（）.

A.Quadrantal spheres
B.Heeling magnets
C.Flinders bar
D.Fore-and-aft magnets

单项选择题Which compensates for errors introduced when the vessel heels over（）.

A.The soft iron spheres on the arms of the binnacle
B.Magnets placed in trays inside the binnacle
C.A single vertical magnet beneath the compass
D.The Flinders bar

单项选择题When relieving the helm，the new helmsman should know the（）.

A.Course per magnetic steering compass
B.Gyro error
C.Variation
D.Maximum rudder angle previously used

单项选择题When crossing the magnetic equator the（）.

A.Flinders bar should be inverted
B.Heeling magnet should be inverted
C.The quadrantal spheres should be rotated 180°
D.Flinders bar should be moved to the opposite side of the binnacle

单项选择题What is used to correct for both induced and permanent magnetism，and consequently must be readjusted with radical changes in latitude（）.

A.Flinders bar
B.Soft iron spheres
C.Fore-and-aft permanent magnets in their trays
D.Heeling magnet