Innovation in coal mining isn't about reinventing the wheel, but about making the wheel more efficient and environmentally friendly.
数学的本质在于它的自由。
Every song tells a story, and every story has a song.
在经济学中，事情的发生比你想象的要慢，然后它们发生的速度比你想象的要快。
Risk more than others think is safe. Dream more than others think is practical.