法律与道德的分离是法律体系的一个必要特征。

The Internet is a place where people can connect, share, and learn.

The Ethernet was designed to be simple, inexpensive, and capable of handling a wide range of applications.

The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.

The future of food security lies beneath the waves—if we farm it responsibly.

解释：对社会有用的，创作百篇也没有害处；对社会无用的，写一章也没有好处。

检验一个经济学家是否优秀的标准，是看他能否比别人更好地解释过去。