问答题 Taking public transit means that you will be sharing your ride with other people. Being considerate while on the system makes everyone’s trip more enjoyable. Courtesy seating (爱心专座) Seats closest to the doors are for persons with disabilities (残障) and/or seniors. People appreciate you offering these seats to them. Food & drink If you are going to eat or drink while riding the system, remember to keep it clean and don’t litter. Take your garbage with you.Make room for others Our system can get very busy during rush hour and we do not want to leave people behind. When boarding a bus, move towards the back to allow space for others. Keep doorways clear In order for people to get on the CTrain, people first need to be allowed to get off. Before you board, please stand back and allow passengers to exit. When on the bus, please stand clear of the exit door and allow people to exit easily. Luggage Please remove your backpack (背包) and put it on the floor. If seating space is limited, ensure that your personal items are not taking away seats from other passengers.《问题》：Where are seats placed on a bus for disabled people?They are closest to_______________________________________________________________________.