解释：道理和事情既没有永远正确的，也没有永远是错误的。
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.
The mathematics of the universe is written in the language of geometry.
