单项选择题
An all-round flashing yellow light may be exhibited by a(n)（）.
A.vessel laying cable B.vessel towing a submerged object C.vessel not under command D.air cushion vessel
单项选择题 An airplane should NOT send which signal in reply to a surface craft?（）
单项选择题 An advantage of using chain lashing on heavy vehicles aboard Ro-Ro vessels is that it（）.
单项选择题 An advantage of the Christmas Tree towing method is to（）.
