单项选择题
（）is not an alarm required by IMO standards to be available on the ECDIS.
A.Deviating from a planned route B.Approach to waypoints and other critical points C.Light house detecting D.Larger scale chart available
单项选择题 （）is not a factor which will affect the accuracy of GPS receiver.
单项选择题 （）is a digitized“picture”of a chart.
单项选择题 The heading of a vessel is indicated by what part of the compass? （）
