革命的道路不是铺满玫瑰的道路。
Every problem in mathematics is a puzzle waiting to be solved, and the joy is in the solving.
纺织行业必须适应不断变化的世界,否则就有被淘汰的风险。
I went to the woods because I wished to live deliberately. I wanted to live deep and suck out all the marrow of life, to put to rout all that was not life.