The tone of the Obama administration's reaction to the settlement freeze was set by U.S.Middle East envoy George Mitchell, who told reporters that while the United States shares Arab concerns about the limitations of Israel's gesture,it is more than any Israeli government has ever done.

VOA: standard.2009.11.25

That's the set up. We're going to run the reactants, the reaction. The reactants are going to turn into products.

这就是我们的装置，我们要进行反应,让反应物变成生成物。

麻省理工公开课 - 热力学与动力学课程节选

Generally, there are a couple of elements that one might set down as in a Petri dish, and wait to see if some chemical reaction might take place, but not at all sure of what it might be.

一般来说，都有几个元素,作者会把它们像放入培养基中一样培养,等待某种化学反应的产生，但对可能的结果却一无所知。

普林斯顿公开课 - 人性课程节选