The human voice is the most beautiful instrument of all, and the most difficult to play.
The day I stop believing I can win is the day I'll stop playing tennis.
所有幼儿教育必须以促进孩子的长此以往发展为目的。
Children aren’t coloring books. You don’t get to fill them with your favorite colors.
科学不是形式逻辑；它和其他创造性艺术一样，需要思想的自由发挥。