The bow is made out of, typically, horse hair from the tails of horses.

大多是用马尾的马鬃制成

耶鲁公开课 - 聆听音乐课程节选

And it's important innovation in several different ways and we're going to talk about this whole science of building artificial organs, devices that are made out of totally synthetic components to replace the function of your natural organs, and the artificial heart is a good example of that.

在很多方向上也做出了重要的创新,我们会讲到,制造人造器官的技术原理,这些装置完全用合成材料制成,能够取代人体器官的功能,人造心脏就是一个很好的范例

耶鲁公开课 - 生物医学工程探索课程节选