这艘游轮上有三百多名乘客。

There were more than 300 passengers ___on ___board the cruise ship.

在机场办理完登机手续后，我终于登机并准备好起飞了。

After I checked in at the airport, I was finally ___on ___board and ready for takeoff.

请在火车出发前确保你所有的行李都已安全存放在车上。

Please make sure all your luggage is safely stowed ___on ___board the train before it departs.