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。