真正的教师会保护学生免受他个人影响。

The only limit to our realization of tomorrow is our doubts of today.

数学是理性的音乐。

The most important thing I have learned is that the best way to get something done is to begin.

The most beautiful thing we can experience is the mysterious. It is the source of all true art and science.

中心地的等级越高，其数量越少。