是可数名词,例如:

1、People are scared to use the buses late at night.人们害怕在深夜乘坐公共汽车。

2、The town is well served with buses and major road links.这座城市乘坐公共汽车很方便,与干线公路的联接也很发达。

3、Buses run frequently between the city and the airport.公共汽车频繁地来往于市区与机场之间。