A.unstabilized displayB.stabilized displayC.composition……

单项选择题A radar contact will remain stationary on a relative motion radar display only when it is（）.

A.on the same course as your vessel
B.at the same speed as your vessel
C.on the same course and speed as your vessel
D.on a reciprocal course at the same speed as your vessel

单项选择题A FICTIVE LINE DISPLAYED ON THE RADAR SCREEN SEPARATING THE FAIRWAY FOR INBOUND AND OUTBOUND VESSELS SO THAT THEY CAN SAFELY PASS EACH OTHER defines（）.

A.Separated line
B.Divided line
C.Reference line
D.Segregated line

单项选择题A Doppler speed log indicates speed over ground（）.

A.at all times
B.in the bottom return mode
C.in the volume reverberation mode
D.only when there is no current

单项选择题A Doppler log in the volume reverberation mode indicates（）.

A.speed being made good
B.speed through the water
C.the set of the current
D.the depth of the water

单项选择题A Doppler log in the bottom return mode indicates the（）.

A.velocity of the current
B.bottom characteristics
C.depth of the water
D.speed over the ground