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