單項(xiàng)選擇題

When visibility is 20 nautical miles, we say that visibility is（）.

A.very good
B.good
C.poor
D.moderate

你可能感興趣的試題

單項(xiàng)選擇題

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

單項(xiàng)選擇題

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