The definition of compound system was given including native system and human system. The definition of certain system and uncertain system were presented.

给出了包含自然系统和人为系统的复合系统定义，以及确定性系统、不确定性系统的定义。

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The deterioration of the ecological system is accelerating because of the dramatic increase of human production and consumption.

由于人类生产和消费活动的急剧增加，生态系统正在加速恶化。

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It is also true that it is difficult to think of a single such system that has not, for better or worse, been substantially modified by human culture.

同样，很难想象一个这样的系统：不管是好是坏，都没有经过人类文化的实质性修改。

youdao

These substances can damage the human nervous system and natural defenses against disease.

VOA: special.2009.06.23

Now, do any of these facts about the digestive system ? make it inappropriate to kiss another human being?

现在，这些关于消化系统的事实有没有,让亲吻另一个人类变得不合适？

耶鲁公开课 - 死亡课程节选

If your roommate comes in and starts trying to tell you facts about the human digestive system, " you say, "Not now."

如果你的室友跑过来开始试图,告诉你有关人类消化系统的事实，你说“现在别说“

耶鲁公开课 - 死亡课程节选

Moreover, the human system is not much different than most mammalian systems and so positing cognitive causes as the source seems sketchy at best.

FORBES: Could Long Commutes Be Making Us Fat?

Many patients fail to respond to currently available therapies, and some of the drugs currently used to treat moderate to severe IBD, including steroids and other immune modulatory agents, can be toxic to the human system.

BBC: News | Health | Bowel disease drug breakthrough

The talk will include "technical content involving head-mounted display hardware and its interaction with the human perceptual system, " with Abrash examining one real world discrepancy to which human perception is sensitive.

ENGADGET: Stay seated: Valve's Team Fortress 2 ported to virtual reality