So there are a couple things, the ping back system is something which we had thought about putting a slide in for.

那么，这里有两个问题，我们曾经考虑加入一页幻灯片来讨论ping back系统。

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Ideally, the system would even allow us to pull an ecosystem back from the borderline.

理想情况下，这个系统甚至会让我们把生态系统从边界处拉回来。

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It has a lens system to focus light onto the film at the back of the camera.

它的镜片系统可以将光线聚焦到相机后部的胶片上。

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Under this system, the company paid the miners, then the miners paid the money back to the company in return for goods and rent.

VOA: special.2009.03.16

But all of you in this room probably remember what we technically call the base 10 system or decimal system because back in grade school or the like, you learned to count and add and subtract numbers by way of columns.

但是，在座的每一位可能都记得,这在小学的时候学的,以10为进制的系统或者十进制系统,通过数列方式学习数数和加减法。

哈佛公开课 - 计算机科学课程节选

The nervous system, the endocrine system which we'll start talking about a little bit today is the system that's responsible for sending signals back and forth between tissues of your body.

还有神经系统,和我们今天将要提到的内分泌系统,内分泌系统主要负责,在体内各组织之间传递信号

耶鲁公开课 - 生物医学工程探索课程节选

The disc was too fragile to play using a needle so the museum, along with researchers at the US Library of Congress and the Lawrence Berkeley National Laboratory, developed an alternative play-back system that used light and a 3D camera to turn its bumps and grooves into sounds.

BBC: Phone pioneer speaks for first time in 128 years

And yet it is a miracle that Voyager 2 managed to send anything back at all, for its main radio system failed soon after launch, and its back-up system proved to be faulty.

ECONOMIST: The long arm of the celestial repairman

The spending reductions all scale back a system of government support that is far too generous to be sustainable.

FORBES: The U.K. Austerity Plan Is a 77% Solution