While talk of what success is and how to define it went on in London, British Foreign Secretary David Miliband told NATO colleagues in Brussels that the current operations should be seen as an opportunity to bring moderate Taliban members into the political process.

VOA: standard.2009.07.27

I don't know how to define it exactly, but I feel so incredibly alive.

我不知道怎么样去定义它，但我真的感到真实的存在感。

普林斯顿公开课 - 人性课程节选

The problem it solves for the cell is how to do I make a barrier around myself to define what's in me and what's outside of me when most of what's around me and what's in me is water.

它为细胞解决的问题是,当我体外和体内大部分都是水情况下,我怎样在自己周围设置一个界线,来区分什么是体内的,什么是体外的

耶鲁公开课 - 生物医学工程探索课程节选