单项选择题
A.nominal range B.luminous range C.charted range D.geographic range
The luminous range of a light takes into account the（）....
单项选择题The luminous range of a light takes into account the（）.
A.glare from background lighting B.existing visibility conditions C.elevation of the light D.observer's height of eye
Restricted areas at locks and dams are indicated by（）.A...
单项选择题Restricted areas at locks and dams are indicated by（）.
A.flashing red lights upstream and fixed red lights downstream B.yellow unlighted buoys C.signs and/or flashing red lights D.red daymarks upstream and green daymarks downstream
Preferred channel buoys indicate the preferred channel ...
单项选择题Preferred channel buoys indicate the preferred channel to transit by（）.
A.odd or even numbers B.the color of their top band C.the location of the buoy in the channel junction D.the buoy's light rhythms
