You might say, well what's the person who studied chemical metallurgy doing teaching chemistry here? Well, after my Ph.D., MIT I came here as a postdoctoral fellow in 1977.

你们可能会问，这个学习,化学冶金学的人怎么会在这教,化学呢，好吧，在我拿到博士学位后，1977年我作为一名博士后来到了。

麻省理工公开课 - 固态化学导论课程节选

And, in fact, once you teach an animal something, if you stop doing the teaching the response goes away and this is known as extinction.

事实上，条件反射形成以后，如果得不到强化,条件反应就会逐渐消失,这就是消退。

耶鲁公开课 - 心理学导论课程节选