In mathematics, you don't understand things. You just get used to them.
                    Recycling should be the last resort, not the first solution. Better design comes first.
                    情感不仅仅是反应;它们是我们最深层次需求和欲望的有力指标。
                    想要制服洋人的祸患,必先熟悉洋人的国情。