Mathematics is a dialogue between the past and the present.
某个命题可以从某一组公理通过某一规则系统推导出来,这一事实本身并不使其为真。
I was neat, clean, shaved and sober, and I didn't care who knew it.
Sustainability is no longer an option; it's a necessity for any business that wants to thrive in the 21st century.