数学的美妙之处在于它常常引导我们发现关于物理世界的真理,而这些真理是我们无法通过其他方式发现的。
The only limit to our realization of tomorrow is our doubts of today.
Maybe I was afraid of change, are you?
用度少,则金价低贱;金价贱,则事情难成。