不要为变老而遗憾。这是许多人求之不得的特权。
The beauty of instrumental variables is that they allow us to see the world in a new light.
Mathematics is the art of giving the same name to different things.
自由民主的未来取决于其应对不平等和政治极化挑战的能力。
新闻自由是英国人所有的公民、政治和宗教权利的保障。
The bond market is the ultimate measure of market confidence.