Under the scheme, Russia would further enrich the uranium to the 20 per cent purity needed for use in a research reactor in Tehran which produces medical isotopes but is running out of fuel.

VOA: standard.2009.10.24

And I'll just point out here also, this is a conversion factor you'll use quite frequently -- many of you, quite on accident, will memorize it as you use it over and over again.

你们会经常用到，所以你们可能,会不小心记住它的值，但我们并不会在,任何考试中。

麻省理工公开课 - 化学原理课程节选

Use "Is there" whenever you want to find out about the existence of a location,

当你想知道一个地点存在的情况时，就用“Is there”句型，

Is there 课堂 - SpeakingMax英语口语达人

And so Richard is learning a grammar of race even while he tries to work out how to use language as a source of power in his family.

所以理查在学习语言的艺术,虽局限于种族,就是他在家里受尽磨难时也在学习语言的魔力。

耶鲁公开课 - 1945年后的美国小说课程节选

This is very important,which is why I am doing it: "If we want to know how fast a human being can run, then it is no use to average out the speed of a "good sample" of the population; it is far better to collect Olympic gold medal winners and see how well they can do.

这话非常重要，是我作这个研究的原因：,“如果想知道人类最快能跑多快，那从好的样本中测出平均数是“,没用的;,而应该收集田径类奥运冠军的信息,看他们能跑多快。

哈佛公开课 - 幸福课课程节选

So what I want to point out with this case in beryllium is that you don't have to use all of the electrons to figure out the bond order, and in fact, once you get to molecules 10 that are from atoms with atomic numbers of 8 or 10, you're not going to want to maybe draw out the full molecular orbital diagram.

我要指出的是,在Be这种情况下,你不需要利用,所有的电子来指导键序，实际上，一旦分子中,原子序数到达了8或者，你也许不想画出,整个分子轨道图。

麻省理工公开课 - 化学原理课程节选