单项选择题
A.accurate only in the Polar regions B.accurate electronic servomechanisms C.hand operated D.accurate only if the vessel is underway
Error may be introduced into a magnetic compass by（）.A....
单项选择题Error may be introduced into a magnetic compass by（）.
A.making a structural change to the vessel B.a short circuit near the compass C.belt buckles D.All of the above
Due to GPS roll over of the clock cycle，GPS receivers m...
单项选择题Due to GPS roll over of the clock cycle，GPS receivers may give the wrong time and position or may lock up permanently on（）.
A.21-Aug-99 B.21-Sep-99 C.Octoer 31，1999 D.31-Dec-99
Deviation which is maximum on intercardinal compass hea...
单项选择题Deviation which is maximum on intercardinal compass headings may be removed by the（）.
A.Flinders bar B.transverse magnets C.fore-and-aft magnets D.soft iron spheres on the sides of the compass
