At The Rockefeller University in New York, she is currently studying how skin forms from precursor stem cells, looking for clues that could help researchers understand how defective stem cells can cause cancers and other disorders.

VOA: standard.2010.03.29

They're derived from a precursor called triacylglyceride, which is as glycerol molecule with three fatty acid chains dangling off of it.

它们来源于一种叫三酰甘油的前体,由甘油分子上连接了,三个脂肪酸链构成

耶鲁公开课 - 生物医学工程探索课程节选

We talked about the artificial hip which is a modern precursor of the splint I talked about before.

我们之前说到的人造髋关节,就是由固定腿部的夹板衍生而来

耶鲁公开课 - 生物医学工程探索课程节选

If someone was telling you this story, is that the first question you would ask? So did she have a precursor? No, probably not. Okay.

如果有人告诉你们这个故事，这会是你们,问的第一个问题吗，可能不是，好的。

耶鲁公开课 - 1945年后的美国小说课程节选

He would have been what Nietzsche in an interesting precursor text calls "historical man."

他就像是尼采在他的一篇有趣的,有关先驱者的文章里提到的“历史上的人“

耶鲁公开课 - 文学理论导论课程节选

I mean it wasn't terrible, it was sort of a precursor to what people are trying to do It flopped miserably, but I'm glad we did it.

其实也没那么糟糕，它就是个先兆，预示了现今人们,很悲惨它失败了，不过我很高兴我们做过。

斯坦福公开课 - 微软CEO-Steve.Ballmer谈科技的未来课程节选

And so, you make not only water vapor, NOX but you make some nitrous oxides, NOX, or nox as it is known, and this is the precursor to smog.

这样不仅仅得到的水蒸气，但是你会得到一些氮氧化物，或者如大家所知到的nox，这是烟雾的前驱体。

麻省理工公开课 - 固态化学导论课程节选

So, she had a precursor. So what? Does that make any difference?

所以，在她之前有过别人，那有怎样，会造成不同吗？

耶鲁公开课 - 1945年后的美国小说课程节选

This is another thing to notice. He's not just making us experience Lolita's name the way he does; he's assuming that there are certain kinds of questions that we will ask. "Did she have a precursor?"

这也值得注意，他不仅让我们体会,他感知到的Lolita的名字，他想象出了,我们可能会提出的问题，在她之前还有别人吗“

耶鲁公开课 - 1945年后的美国小说课程节选