中心地的等级越高，其服务的区域越大，此类中心地的数量越少。

We must balance the need for affordable energy today with the imperative of building a sustainable energy future.

"A good line of poetry should surprise you twice: when you write it and when you read it."

If you want something you've never had, you must be willing to do something you've never done.

"Writing is a way of thinking, a way of discovering what you really believe."