American Heart Association spokesman Dr.Donald LaVan explains why that change in the arteries is significant.

VOA: standard.2010.03.04

Why the change in infectious diseases?

为什么感染性疾病致死率发生了变化

耶鲁公开课 - 生物医学工程探索课程节选

Because if the change was not possible on the individual level, ? on the society level,why am I doing what I am doing?

因为如果从个人层面或社会层面来说，改变都是不可能的，那我在这里干什么？

哈佛公开课 - 幸福课课程节选

So you start with your basic model, then you add in, you enrich the model, and you see if the results change, and that'll help you explain why you're getting different results in different settings.

你们从最原始的模型开始,加入约束条件来丰富这个模型,然后检验结果是否有变,这能帮助我们解释,为什么在不同条件下结果是不同的

耶鲁公开课 - 博弈论课程节选

I believe that and why do we need to have it as a basic premise of the course, '?" as opposed to change is illusive?"

我相信这一点，但为什么我们需要把它,作为课程的基本前提，而不说'改变是虚幻的“

哈佛公开课 - 幸福课课程节选