Take the example of Facebook. It was launched in two thousand four as a social network just for Harvard students.

VOA: special.2009.09.14

And as an example, let's take sulfuryl chloride, SO2, Cl2 make it a little complicated, Cl2, right, so don't worry about these compounds.

让我们用SO2作为一个例子，这有点难度，对，还有，不要担心这些化合物。

麻省理工公开课 - 固态化学导论课程节选