单项选择题

An electronic depth finder operates on the principle that（）.

A.radio signals reflect from a solid surface
B.sound waves travel at a constant speed through water
C.radar signals travel at a constant speed through water
D.pressure increases with depth

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热门试题

单项选择题An ECDIS is required to display which information?（）

A.Water temperature
B.Climatology data
C.Speed of advance
D.Depth contours

单项选择题An ECDIS is required to display which information?（）

A.Soundings
B.Waypoints
C.Meteorological data
D.Radar targets

单项选择题An ECDIS is required to display which information?（）

A.Radar targets
B.ARPA vectors
C.Hydrographic data
D.All of the above

单项选择题A tall object with a light on or near the shore，to act as a guide or warning to mariners is called（）.

A.beam
B.radar
C.light beacon
D.reflector

单项选择题A radar range to a small，charted object such as a light will provide a line of position in which form?（）.

A.Straight line
B.Arc
C.Parabola
D.Hyperbola