单项选择题 A bold reef is a reef（）.

单项选择题 （）means the curve on the earth’s surface which cuts all the meridians at the same angle.

单项选择题 （）is the process by which the position of the vessel at any moment is found by applying the last well-determined position to the run that has been made since，using for this purpose the ship’s course and the distance being those indicated by log.