Disciplining yourself to do what you know is right and important, although difficult, is the highroad to pride, self-esteem, and personal satisfaction.

Logic is the foundation of all mathematical reasoning.

The tyranny of a prince in an oligarchy is not so dangerous to the public welfare as the apathy of a citizen in a democracy.

以往花费许多力量也不能推动它，今天在水中间却能自在地移动。

别害怕独自站立。

煤炭行业必须进化，否则有过时的风险。适应是生存的关键。