单项选择题
A line of position derived by radar range from an identified point on a coast will be a(n) （）.
A.straight line B.arc C.parabola D.line parallel to the coast
单项选择题 A head on situation shall be deemed to exist at night when a power-driven vessel sees another power-driven vessel ahead and （）.
单项选择题 The Sailing Directions contain information on （）.
单项选择题 You will find information about the duration of slack water in the （）.
