你可能感興趣的試題

A.two red lights at night and two black balls during daylight
B.two red lights at night and three black balls during daylight
C.three red lights at night and two black balls during daylight
D.three red lights at night and three black balls during daylight

A.two all-round red lights in a vertical line
B.anchor lights and sidelights
C.two all-round white lights in a vertical line，sidelights and a stern light
D.two all-round red lights in a vertical line，sidelights，and a stern light