你知道得越多，就越意识到自己知道得多么少。

【译文】兔子死尽猎犬被烹，敌国灭亡谋臣遭殃。

世界因你的榜样而改变，而不是因你的观点。

You are never too old to set another goal or to dream a new dream.

True sustainability means leaving the land better than we found it for future generations.

The great challenge of our time is to build institutions that can manage the complexity of modern societies.

友谊是心灵的桥梁。