A.上綠下白 B.上白下綠 C.上紅下白 D.上白下紅
A.0.9m;0.9nmile B.0.9m;1nmile C.1m;0.9nmile D.1m;1nmile
A.白燈 B.黃燈 C.紅燈 D.綠燈