单项选择题
A.An atomic time standard B.Daylight Savings Time C.Eastern Standard Time D.Greenwich Mean Time
The receiver uses()satellites to compute latitude,longi...
单项选择题The receiver uses()satellites to compute latitude,longitude,altitude,and velocity.
A.one B.two C.three D.four
The operator of the ship’s radiotelephone,if the radiot...
单项选择题The operator of the ship’s radiotelephone,if the radiotelephone is carried voluntarily,must hold at least a().
A.Mate's license B.Restricted radiotelephone operator permit C.Second-class radio operator's license D.Seaman's document
The operation of which aids to navigation may be suspen...
单项选择题The operation of which aids to navigation may be suspended during war or national emergency().
A.Navigational satellites B.Loran C.Omega D.Any of the above