So, our detection devices are a little bit limited here today, we're actually only going to be using our eyes, so that means that we need to stick with the visible range of the electromagnetic spectrum.

我们今天所有的探测仪器十分有限，实际上我们要用我们的眼睛来观测，这意味着我们只能看到,电磁谱中的可见光区间。

麻省理工公开课 - 化学原理课程节选

It used to be a lot easier to be physically active then it is today, and we'll discuss this later in the class, but energy saving devices all over the place.

在过去,人们比现在从事更多的体力活动,这一点我们以后再讲,帮助你省力的装置,如今随处可见

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选