Today we tell you about one of the few prisons in America that offer college-level classes: San Quentin State Prison in California.

VOA: special.2011.07.07

So, if you use a black lamp or something and you excite something up to a higher energy level and then it relaxes back down to its lower energy state, it's going to emit a new wavelength of light, which is going to be visible to you.

如果你用一个紫外灯或别的,东西把某种分子激发到,更高的能级，然后它会掉回,到低能级，它就会释放,一个新的波长的光,这个光是可见的。

麻省理工公开课 - 化学原理课程节选

First, the Treaty declared that the individual sovereign state would henceforth become the highest level of authority; you might say, putting an end once and for all " to the universalist claims of the Holy Roman Empire.

第一，条约宣称,各个主权国家,都因此而成为各自国家里最高的权力;,永远终结了,普遍意义上的“神圣罗马帝国。

耶鲁公开课 - 政治哲学导论课程节选

Ambassador Rice said she expects a large number, if not all, of the 15 Security Council members to be represented at the head of state or government level.

VOA: standard.2009.09.02

So if we go to the ground state, what you see is we're at that lowest energy level, and we only have one possibility for an orbital, because when n equals 1, that's all we can do.

如果我们在基态上，你可以看到，我们在能量最低的态上，只有一种，可能的轨道，因为n等于1，只有这种可能。

麻省理工公开课 - 化学原理课程节选

The government's diversity drive for the grandes ecoles has prompted a call by a group of academics for the state to level the playing field in other areas, like offering more housing and scholarships to poorer students attending these institutions.

VOA: standard.2010.02.02

But the U.S.reaction to Thursday's attack was at an unusually high level, with both President Obama and Secretary of State Hillary Clinton issuing written statements expressing sympathy to the families of victims and calling for the attackers to be held accountable.

VOA: standard.2010.07.16