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
单项选择题 The radio waves used for radar are very short，only（）long.
单项选择题 The radar control used to reduce sea return at close ranges is the（）.
单项选择题 The radar control that shortens all echoes on the display and reduces clutter caused by rain or snow is the（）.
