自由意味着责任,这就是为什么大多数人害怕自由。
Liberty means responsibility. That is why most men dread it.
可持续发展已不再是一种选择,而是我们对后代的责任。
每个数学问题都有解答;挑战在于找到它。
I love the man that can smile in trouble, that can gather strength from distress, and grow brave by reflection.