That is our mission,". "And the president described it in no uncertain terms in his inaugural when he said, 'Our nation is at war against a far-reaching network of violence and hatred.' And to win this war against al-Qaida, the administration continues to be unrelenting, using every tool in its toolbox and every arrow in its quiver,"

VOA: standard.2009.08.06

So now we're just counting up our orbitals, an orbital is completely described by the 3 quantum numbers.

所以现在我们只要把这些轨道加起来，一个轨道是由３个量子数完全确定的。

麻省理工公开课 - 化学原理课程节选

If we have the molecule ethane, then what we're going to have first is our sigma bond that we described between the two carbons.

如果我们有乙烷分子，那我们首先有,碳碳之间的sigma键。

麻省理工公开课 - 化学原理课程节选