如何使用 "bus" 造句

1. The bus is leaving from the gate 15 .
这辆巴士从15号门离开。
2. Is this the bus to the library ?
这是去图书馆的公交车吗?
3. The cheapest way to travel is by bus .
最便宜的旅行方式是坐公共汽车。
4. Sitting alone on that bus was awful .
一个人坐在公车上的感觉糟透了。
5. I 'd been demoted to taking the bus .
我被降级到要去搭大巴。