To be happy, it is necessary to forget as well as to remember.

科学的进步不是一条直线，而是一个螺旋，总是在前进，又总是回到起点。

Innovation in coal mining isn't about reinventing the wheel, but about making the wheel more efficient and environmentally friendly.

The human being is essentially self-determining; he becomes what he wills himself to be.

我越看人民的代表，就越钦佩我的狗。

无论成本如何，质量永远不应妥协。