悲伤是爱变成了永恒的缺失。
Grief is love turned into an eternal missing.
The best science is done with an open mind and a willingness to learn.
No matter what he does, every person on earth plays a central role in the history of the world. And normally he doesn't know it.
我看到了，我忘记了；我听到了，我记住了；我做过了，我理解了。