"The best and most beautiful things in the world cannot be seen or even touched - they must be felt with the heart."

Even the strongest man needs someone to stand by him.

Die Kunst des Lebens besteht darin, Schwierigkeiten zu überwinden, ohne sie zu besiegen.

数学是宇宙的语言，通过它，我们可以理解支配我们世界的基本原则。