距离不仅仅是一个物理概念，还是一个社会和经济概念。

I have to say to myself that some birds aren't very close. Their feathers are just too bright. When they fly away, you know it's a sin to lock them up, and you'll be inspired by them. Still, the place you live in is that much more drab and empty that they're gone. I think I really miss my friends.

The cement industry must evolve or become obsolete.

唯一真正富有的是那些不想要比他们拥有的更多的人。

每一个数学问题都是一个等待解决的谜题，每一个解答都是向理解现实结构迈进的一步。