单项选择题
Vessel required to have an Automatic Radar Plotting Aid must have a device to indicate the（）.
A.speed of the vessel over the ground or through the water B.distance to the next port C.time of the next navigational satellite pass D.None of the above
单项选择题 To determine if risk of collision exists，a vessel which is fitted with radar must use（）.
单项选择题 The shoreline along Rocky Point should give a good radar return because（）.
单项选择题 The radio waves used for radar are very short，only（）long.
