每一个天使都是可怕的。
I don’t let success define me, I let it refine me.
智者在自己的心灵中寻找幸福,愚者则在外部追逐。
Natural experiments are a powerful tool for understanding causal relationships in the real world.
One who never turned his back but marched breast forward, never doubted clouds would break.
"You can't knock on opportunity's door and not be ready."