单项选择题
A.Loran C B.Direction Finder C.Gyro- compass D.Radar
When visibility is 20 nautical miles, we say that visib...
单项选择题When visibility is 20 nautical miles, we say that visibility is（）.
A.very good B.good C.poor D.moderate
Our ship has not been to shipyard for a long time, the ...
单项选择题Our ship has not been to shipyard for a long time, the fouling on the ship’s hull greatly decreases her（）.
A.resistance B.weight C.speed D.displacement
Radar is not only to obtain（）,but also to measure their...
单项选择题Radar is not only to obtain（）,but also to measure their distance away from you.
A.brightness of obtain B.color of targets C.shape of targets D.bearing of objects
