Good design is invisible; you only notice it when it's bad.
Ignorance is not innocence but sin.
The man who wants to lead the orchestra must turn his back on the crowd.
教育学中的实验方法不仅是研究的工具,更是理解教育过程的基本原则。
海洋从四面八方包围着地球,而我们只居住在其中一小部分。