当年的年轻人已变成了花下之尘。

The opening up of new markets, foreign or domestic, and the organizational development from the craft shop and factory to such concerns as U.S. Steel illustrate the same process of industrial mutation—if I may use that biological term—that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one.

Combinatorics is like the art of counting without actually counting.

【译文】 孔子说：“不怕没人了解自己，就怕自己没有能力。”