In fact,Lillian Moller Gilbreth is known as the mother of modern management.

VOA: special.2009.05.04

In fact, of all the systems of cellular differentiation that are known in our bodies, probably hematopoiesis is the best known.

事实上,我们体内已知的,所有由细胞分化成的系统中,造血系统也许是最为人所熟知的

耶鲁公开课 - 生物医学工程探索课程节选

By the way, I've never known whether it is a fact.

其实我也从来都不知道这句话这是不是真的。

耶鲁公开课 - 文学理论导论课程节选

And, in fact, a computer program has come up with a proof that, as far as was known, nobody in the world had ever come up with before.

而实际上,电脑程序的证明方式,据目前所知,是前人们从未曾提出过的

耶鲁公开课 - 死亡课程节选

So what actually turns out the reality is that h e 2 does exist, but it exists as the weakest chemical bond known, and it wasn't, in fact, even found to exist until 1993, so I can assure you this is not a bond that you see very often in nature, and it is a very, very weak bond.

实际上He2键是存在的，但它是目前所知的最弱的键，直到1993年它才被发现，所以我可以向你们保证在,自然界你们不可能经常看到它，它是种非常非常弱得键。

麻省理工公开课 - 化学原理课程节选