"The brain-machine interface is a system that allows disabled people, people suffering from physical disabilities to communicate with external world and also to control devices."

VOA: special.2011.04.04

Here there's an expansion going on, so the system is doing work to the external world.

这里发生了膨胀,所以系统对外界做功，活塞被推出来。

麻省理工公开课 - 热力学与动力学课程节选

I mean maybe up the street we whisper, but here we know it. And, so here is a different kind of system where we have a constant external pressure.

或许在街上你们低声细语，但在这里不应该这样，这是另一个系统,我们有一个恒定的外压强。

麻省理工公开课 - 热力学与动力学课程节选

The respiratory system, for example, the renal system, the digestive system, these are examples - three examples of organ systems that contact the external environment.

例如,呼吸系统,泌尿系统,消化系统,这些系统,这三个系统,与外环境相联系

耶鲁公开课 - 生物医学工程探索课程节选

We've talked about the interesting way in which the digestive system contacts the external environment.

我们会讲到,消化系统与外环境之间十分有趣的联系

耶鲁公开课 - 生物医学工程探索课程节选

Depending on what you call external and internal environment, this path that I'm tracing here, deep within your digestive system, is really directly connected to the outside world through both ends.

基于你们所谓的外环境和内环境,我在这里我所指的消化系统内部通路,它的两端确实与外界环境直接相通

耶鲁公开课 - 生物医学工程探索课程节选

It's the pressure the external world is applying on this poor system here.

V是气体初态和,末态的体积之差。

麻省理工公开课 - 热力学与动力学课程节选