Well, if this thing is going to vibrate for any length of time it better be a standing wave.

好的，如果它在任意时间振动,那它就是驻波。

麻省理工公开课 - 固态化学导论课程节选

How long" can be used in a question and it refers to a length of time or a length of distance.

How long” 句型用于问句中，用来询问时间或距离的长短。

How long课堂 - SpeakingMax英语口语达人

OK. In the length of time it takes for the light to get from that bulb to the table, this machine processes two operations.

好，在灯光从灯泡到,桌子的这段时间内，电脑已经进行了两次运算了。

麻省理工公开课 - 计算机科学及编程导论课程节选

It's - a suture or a stitch has to hold the wound closed so it has to have certain mechanical strength and imagine the problem of making something that's dissolvable so it disappears but also is strong enough to hold a wound closed reliably for a length of time.

能够拉紧切口的缝合线,就必须具有一定的机械张力,大家想像一下制造这种缝合线的难度,身体组织不仅要能吸收这种缝合线,而且这种线必须有足够的张力,一定时间内能够拉紧切口

耶鲁公开课 - 生物医学工程探索课程节选

A gig is 10 to the 9, so it does two operations in the length of time it takes light to get from one foot off the table down to the table. That's amazing.

因此光行进一英尺的,时间内电脑可以,进行两次基本运算,这太神奇了。

麻省理工公开课 - 计算机科学及编程导论课程节选