There has never been a regime in history that was so single-mindedly devoted to the end of producing that rarest and most difficult species of humanity called simply philosopher.

历史上从没有一个政体,会如此专一地致力于,催生最稀有,最难得的人类物种,即哲学家。

耶鲁公开课 - 政治哲学导论课程节选

When it cuts it leaves sticky ends or un-base paired single stranded regions on each end of the part its cut and that's just a property of many restriction enzymes; not all, some cut blunt,just right down the middle.

它切割后会留下两个粘性末端,或者未配对的单链部分,这是许多限制性内切酶的特性,但不是全部,有些限制性内切酶是从中间钝切的

耶鲁公开课 - 生物医学工程探索课程节选