数学是一项协作的努力。没有人可以单独完成。

The typewriting machine, when played with expression, is not more annoying than the piano when played by a sister or near relations.

生活是世界上最罕见的事情。大多数人只是存在，仅此而已。

Life does not ask what we want. It presents us with options.

投资清洁煤炭技术不是开支，而是对我们未来的投资。