能见度不良时，鸣放规定汽笛，通知我上驾驶台。

Whenthe vis. becomes poor, sound the whistle as rule and call me on bridge.

youdao

能见度不良时，鸣放规定汽笛，通知我上驾驶台。

Whenthe vis. becomes poor, sound the whistle as rule and call me on bridge.

youdao