单项选择题
A.radar scanning B.radar plotting C.compass bearings D.All of the above
The shoreline along Rocky Point should give a good rada...
单项选择题The shoreline along Rocky Point should give a good radar return because（）.
A.the shore is bluff and rocky B.of offshore exposed rocks C.submerged reefs cause prominent breakers D.the lookout tower is marked with radar reflectors
The radio waves used for radar are very short，only（）lon...
单项选择题The radio waves used for radar are very short，only（）long.
A.a few centimeters B.a few fathoms C.a few meters D.a few feet
The radar control used to reduce sea return at close ra...
单项选择题The radar control used to reduce sea return at close ranges is the（）.
A.gain control B.sensitivity time control C.fast time constant D.pulse length control
