煤炭的真实成本必须既考虑其即时价值,也考虑其对社区和生态系统的长期影响。
There is danger from all men. The only maxim of a free government ought to be to trust no man living with power to endanger the public liberty.
A true mathematician is always a student, always learning.
The more surreal it is, the more I like it.