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.
It has been said that man is a rational animal. All my life I have been searching for evidence which could support this.
成功是一个糟糕的老师，它诱使聪明人认为他们不会失败。
粮食安全是一个需要地方行动的全球性问题。
The world is a great clock, and we are the hands.