单项选择题
Although manual plotting for CPA works well，the workload can become overwhelming when confronted with（）.
A.one target B.two targets C.three targets D.a large number of targets
单项选择题 （）typically extends from close as 0.1 nautical miles out to 32 NM.
单项选择题 （）is not used in modern radar.
单项选择题 （）is not a job of the radar antenna.
