单项选择题
A.flashing B.pulsating C.occulting D.alternating
A light having characteristics which include color vari...
单项选择题A light having characteristics which include color variations is defined as（）.
A.switching B.alternating C.oscillating D.fluctuating
A light characteristic of composite group flashing indi...
单项选择题A light characteristic of composite group flashing indicates that there is a(n)（）.
A.sharp turn in the channel B.narrowing in the channel at that point C.junction in the channel D.obstruction that must be left to port
A lateral system buoy displaying a quick light（）.A.shou...
单项选择题A lateral system buoy displaying a quick light（）.
A.should be passed close aboard on either side B.indicates that special caution is required C.is used at a channel bifurcation or junction D.is painted with red and white vertical stripes
