单项选择题
A.bearing circle B.pelorus C.bearing bar D.alidade
At the master gyrocompass，the compass card is attached ...
单项选择题At the master gyrocompass，the compass card is attached to the（）.
A.spider element B.sensitive element C.link arm D.pickup transformer
Before switching on gyro-compass，you should make sure t...
单项选择题Before switching on gyro-compass，you should make sure that the power supply on board is（）.
A.high or low B.AC or DC C.strong or weak D.on or off
Calibration Stations give special transmissions for the...
单项选择题Calibration Stations give special transmissions for the calibration of ship’s（）.
A.gyro-compass B.marine radar C.DF D.navigational satellite
