局部和全局现象之间的相互作用是数论中反复出现的主题。
皮革的未来在于传统与技术之间的平衡。
Coal has been the backbone of industrial progress, but its future must balance economic needs with environmental responsibility.
译文：成家立业后才知道柴米的贵重，自己抚养孩子时才知道报答父母的恩情。赏析：世事的艰难，只有当我们亲身经历后才会懂得，生活的不易，只有当我们尝遍酸甜苦辣咸才会明白。
我们就是我们假装成为的样子，所以我们必须小心我们假装成为什么。
The question I ask myself like almost every day is, 'Am I doing the most important thing I could be doing?'
