The past is always changing. It is not fixed. The past is not stable.
过去总是在变化。它不是固定的。过去并不稳定。
成为作家就是成为生活的间谍。
Economic history teaches us that change is possible, but it is rarely easy.
A mathematician's best work often comes from seeing connections where others see none.
追求数学真理是一项崇高的努力。