每一个挑战都是变得更强大、更睿智的机会。
If you want to fly, you have to give up the things that weigh you down.
The beauty of instrumental variables is that they allow us to see the world in a new light.
过去是一个外国;他们在那里做不同的事情。
休息隶属于工作,正如眼睑隶属于眼睛。