This is maybe not widely appreciated, but every decade that goes by we do a better job of incentvizing people and preventing them from being discouraged by risks.

也许在当下，一些措施看似并非有效，但若以十年跨度回望,我们所采取的措施确实能有效地激励人们,并且防止他们因风险受挫。

耶鲁公开课 - 金融市场课程节选

They had to give some of them the real vaccine and some of them a placebo vaccine in order that they could really tell if the vaccine worked; you have to have it placebo controlled.

研究者们还须给部分孩子接种真正的疫苗,给另外一些孩子接种空白疫苗,以分辨疫苗是否真的有效,所以你必须使用安慰剂作对照

耶鲁公开课 - 生物医学工程探索课程节选