单项选择题
A.Middle of the channel B.Starboard side of the channel C.Port side of the channel D.Side of the channel that has the widest turns
A.stay near the middle of the channel B.keep to the starboard side of any vessels you meet C.exchange whistle signals with any other vessels in the channel D.keep to the side of the channel which lies to your starboard
A.a light signal of at least five short and rapid flashes B.one prolonged,one short,one prolonged,and one short whistle blasts C.four short whistle blasts D.two short whistle blasts