"What we know from research on teen brain development, is that teens don't really have fully developed brains until they're twenty-five years old.

VOA: special.2010.07.01

So, we know from our calculation that we can do over here, that this bond is polar.

我们通过计算都知道,这个键是非极性的。

麻省理工公开课 - 固态化学导论课程节选

But the reality that we know from our quantum mechanical model, is that we can't know exactly what the radius is, all we can say is what the probability is of the radius being at certain different points.

我们不可能准确的知道,半径是多少，我们只能说，它在不同半径处，的概率是多少，这是,量子力学。

麻省理工公开课 - 化学原理课程节选

As we know from the Hatch case, this makes it taxable to the recipient.

FORBES: Casey Anthony on Trial, Liened by IRS

In any event, we know from history that periodic market panics and crashes are common occurrences.

FORBES: Extraordinary Popular Delusions Lead All The Way To Adam

We know from our history that change is hard, just like that 101-year-old supporter knew.

WHITEHOUSE: Remarks by the First Lady at a Campaign Event