单项选择题
A line connecting all possible positions of your vessel at any given time is a（）.
A.longitude line B.latitude line C.line of position D.fix
单项选择题 A large navigational buoy (LNB) is painted（）.
单项选择题 A fairly accurate estimation of a ship’s position can be calculated by a technique known as（）.
单项选择题 A dead reckoning (DR) plot（）.
