on bus还是on the bus

常用的是on the bus，强调坐公车这个概念,表示出行的交通方式。如a thief in the bus 公交车上的小偷，just in the bus 不过这是在车上的效果。

Police in Kunming have launched a manhunt for a suspect in the bus bomb blasts case.

昆明警方已开始对公交车爆炸案的犯罪嫌疑人实施大追捕行动。

Didn\'t you find the baggage left in the bus?

你在巴士上有没有发现遗失的行李？

So, the driver had played a big joke on everybody in the bus.

时，全体乘客轰然大笑，原来司机对全车乘客开了一个大玩笑。

The passengers all laughed when the driver cried,“April fool!” So，the driver had played a big joke on everybody in the bus.

当司机大声说“四月傻瓜！” 时，全体乘客轰然大笑，原来司机对全车乘客开了一个大玩笑。

A bike is in the bus.

一辆自行车在这辆公共汽车里面。