A.①② B.①③ C.②③ D.①②③
A.水位下落,航道變窄 B.枯水期,船舶在急彎段航法的需要 C.為保證船舶航行和會(huì)讓安全 D.為保證船舶追越時(shí)的安全
A.船位與航向、轉(zhuǎn)向點(diǎn)與吊向點(diǎn) B.船位與航向、轉(zhuǎn)向點(diǎn)與過(guò)河點(diǎn) C.船位與航向、吊向點(diǎn)與過(guò)河點(diǎn) D.落位與航向、轉(zhuǎn)向點(diǎn)與吊向點(diǎn)