阅读中提出三个可能原因：

听力反驳：

学术讨论写作：

Doctor Gupta

In the next few weeks, we'll be talking about urban traffic management. Let's begin by discussing one popular idea--creating car-free central zones. Some cities around the world have recently designated their downtown areas as being automobile-free which means that vehicles are not allowed to enter the city centers. Do you think that more cities should make their central zones car-free？Why and why not?

Claire

I support the idea of establishing car-free central zones because this will result in one important benefit for city residents-it will be better for their health. Instead of driving everywhere, people will be encouraged to walk or cycle more. It would be a great way to incorporate exercise into people's routines. 

Paul

It sounds like a good idea, but I'm skeptical. My main concern is that many businesses located in the city centers, such as shops and restaurants, may suffer because the customers will no longer be able to reach those businesses by car. For some customers, if they can't drive, they won't go at all.

主题：是否应设立更多无车市中心区，以及其对居民健康和企业经济的影响。