1 Where is this bus's starting stop and the final stop (公共车站叫bus stop.而station 用于火车站）
2 Where does this train start and where terminate?(后一个where 省略了 does this train)
from where and to where does this train go?
3 How long does the bus take to run from last leaving?What's the bus's schedule?
How often does this bus go?
4 The bus is scheduled to run every 20 minutes.
The bus runs every 20 minutes