单项选择题
A.The ARPA will generate data as if the target was still being tracked by radar
B.The ARPA will give an audible and/or visual lost target alarm
C.The ARPA will generate data based on sea return echoes from the vicinity where the target was lost
D.The ARPA has lost all memory of the target and must recompute the target data
单项选择题 The development of（）led to the fully automatic ARPA systems installed on commercial ships.
单项选择题 The（）has a built-in world map; most areas are displayed on a scale of 4000 nm from the top to the bottom of the screen，and can be zoomed in to 150 nm.
单项选择题 Radar reflectors are required for（）.