Every man is his own greatest enemy， and as it were his own murderer.

圆的周长大于任何内接等边多边形的周长，小于任何外切多边形的周长。

Generations to come will scarcely believe that such a one as this walked the earth in flesh and blood.

每个生命都包含自己的奥秘，传记作者必须尊重那些不可知的部分。