And that is a preface to an idea of computational complexity we're going to come back to.

这是我们日后,要讲的计算复杂度的,一个前言。

麻省理工公开课 - 计算机科学及编程导论课程节选

OK. That takes care of the administrivia preamble.

好的，这就是一点儿关于课程的前言。

麻省理工公开课 - 计算机科学及编程导论课程节选

The law code of Hammurabi is available to us and there's a preface to it in which he basically explains why you should obey the rules that he now is laying down for you.

汉莫拉比法典为我们提供了证据,汉莫拉比在法典的前言中向我们解释了,为什么要遵守他颁布的法律

耶鲁公开课 - 古希腊历史简介课程节选