30.Reference line is a line on the radar screens in VTS Centers and/or electronic seacharts
separating the fairway for inbound and outbound vessels so that they can safely
pass each other.
(A)show up
(B)appearance
(C)displayed
(D)setting
"Reference line is a line on the radar screens in VTS Centers and/or electronic sea charts displayed, separating the fairway for inbound and outbound vessels so that they can safely pass each other."