You would first get exposed in children-- in childhood and then at a point when you're susceptible to the disease.

在儿童期这个较容易受病毒感染时期,第一次接触该病毒,就会引起发病

耶鲁公开课 - 生物医学工程探索课程节选

Some, like the smallpox vaccine on one exposure generates a very high response that lasts for many years so you don't need a boost.

有一些疫苗,比如接触一次天花疫苗后,人体就能产生高水平的免疫应答,并持续很多年,所以无需再次接种

耶鲁公开课 - 生物医学工程探索课程节选

So I'm going to ask you to come at the New Testament,though, from the outside. If you feel like you know something about it, put those aside for the moment, because when we do the class we'll be trying to get you to see this document as if for the first time, to see early Christianity completely as if for the first time.

所以我要求你们客观地研究新约，如果你觉得你对它略知一二，就请先遗忘片刻，因为我希望你们上课阅读文本时,当做与其第一次接触，第一次接触早期基督教。

耶鲁公开课 - 新约课程节选

A typical problem that you may have done in your first pass at Newton's law, someone tells you a force of 36 Newtons is acting on a mass of whatever, 4 kilograms; what's the acceleration?

在你们第一次接触牛顿定律时,可能见过这么一道典型题目,告诉你,一个 36 牛的力,作用在一个物体上,4 千克吧,问加速度是多少

耶鲁公开课 - 基础物理课程节选

The Greeks are in touch with them again and they borrow styles, copy styles, maybe in the early day they used some of the craftsmen from out there or maybe their own craftsmen picked it up.

希腊人又一次与他们接触了,借鉴并复制了他们的风格,也许在早期他们雇佣一些那些地方的工匠,或者让他们自己的工匠学习

耶鲁公开课 - 古希腊历史简介课程节选

I have to believe that whoever came up with that theory for the first time was aided in coming to it by thinking about the end of the Roman Empire, when something precisely like that did happen.

我想任何人第一次接触该理论,都会自动联想到罗马帝国的衰亡,进而支持该理论,因为类似的事情确实曾经发生过

耶鲁公开课 - 古希腊历史简介课程节选

One thing I do want you to remember is that IgM class antibodies are the antibodies produced on first exposure.

我希望你们记住的一点是,IgM类抗体是人体在,第一次接触抗原时产生

耶鲁公开课 - 生物医学工程探索课程节选