单项选择题
What will cause the ARPA to emit a visual alarm，audible alarm，or both?（）
A.An acquired target entering into a guard zone B.A tracked target lost for one radar scan C.A tracked target entering your preset CPA-TCPA limits D.A target being initially detected within a guard zone
单项选择题 What provides little or no indication that a vessel is dragging anchor? （）
单项选择题 What is TRUE when operating in fog and other vessels are detected by radar?（）.
单项选择题 What is TRUE of the history display of a target’s past positions on an ARPA?（）
