And this is a very fast speed, of course, it's about 700 million miles per hour. So, one way to put that in perspective is to think about how long it takes for a light beam to get from earth to the moon. Does anyone have any guesses? Eight seconds, that sounds good.

当然这是一个非常快的速度，它大约是每小时7亿英里,为了更形象化，我们,看看光从地球到月球,需要多少时间，你们猜猜是多少？,8秒，猜的不错。

麻省理工公开课 - 化学原理课程节选

because you need to know like, how fast the shutter speed and all that stuff,

因为你必须知道，像快门的速度，还有其他这一类东西，

体育相片的魅力 - SpeakingMax英语口语达人

A clock tells you what time it is, but you can also say what time it is by seeing how fast the particle is moving because you know it started with some speed.

时钟能告诉你现在的时间,但你也可以通过测量质点速度,来判断当前的时间,因为你知道它的初速度

耶鲁公开课 - 基础物理课程节选

% So 1% the speed of light. I would say that is relatively fast. That is a pun.

所以说是光速的,相对来说有点快，这是一个双关语。

麻省理工公开课 - 固态化学导论课程节选

This is very important,which is why I am doing it: "If we want to know how fast a human being can run, then it is no use to average out the speed of a "good sample" of the population; it is far better to collect Olympic gold medal winners and see how well they can do.

这话非常重要，是我作这个研究的原因：,“如果想知道人类最快能跑多快，那从好的样本中测出平均数是“,没用的;,而应该收集田径类奥运冠军的信息,看他们能跑多快。

哈佛公开课 - 幸福课课程节选

fast train, high speed train.

它是快速火车，高速火车。

介绍欧洲之星 - SpeakingMax英语口语达人