The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.

Mathematics is not just about numbers, equations, computations, or algorithms: it is about understanding.

我们生产的每一块塑料都应该有明确的再利用或回收路径。

变得更幸福既需要意愿也需要正确的方法。