为明天做准备的最好方法就是集中你所有智慧,所有的热忱,把今天的工作做得尽善尽美。
过去不是为了生活其中;它是一个结论的源泉,我们从中汲取以行动。
The only thing that is constant is change.
The beauty of instrumental variables is that they allow us to see the world in a new light.