中心地的空间分布遵循基于经济原则的系统模式。
Every man is born as many men and dies as a single one.
The only way to learn mathematics is to do mathematics.
"I have come to believe that a great teacher is a great artist and that there are as few as there are any other great artists. Teaching might even be the greatest of the arts since the medium is the human mind and spirit."
In mathematics, the art of proposing a question must be held of higher value than solving it.