补全对话（每小题1分，共5分）
Dave：Can I ask you some questions, Sally?
Sally：Sure! What’s up?
Dave：   
Sally：Yes, it’s a little far.
Dave：   
Sally：First, I walk to the bus station and then I take the bus.
Dave：How long do you spend on the bus?
Sally：   
Dave：Do you need to walk after you get off the bus?
Sally：   
Dave：How many students in your class take the bus to school?
Sally：  
Dave：Thanks a lot.