Whether we are describing a king, an assassin, a thief, an honest man, a prostitute, a nun, a young girl, or a stallholder in a market, it is always ourselves that we are describing.

数学的力量来自于它的抽象和概括能力，将具体问题转化为普遍真理。

煤炭工业是美国的支柱。

The bakery business is as much about science as it is about art.