美不是艺术的目标，而是它的副产品。
Beauty is not the goal of art, but its byproduct.
The only thing you can do is give all you have on that particular day.
The climate doesn't care about political boundaries.
工具变量的美妙之处在于它们让我们以新的视角看世界。
做你自己，别人都已经有人做了。