We did a demonstration there with two vibrating objects with a spring, but yet the center of mass was moving with a constant velocity.

我们做过演示的，弹簧连接两个振动物体，但是质量重心，却保持稳定速度。

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A good demonstration of the relativistic change of mass can be observed experimentally on very fast-moving particles.

一个证明相对质量改变的好实验，可以通过在高速运动的粒子上观察到。

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On the basis of exploration and demonstration, SBSD bulk setter and mass flowmeter was combined to replace the oval gear setters.

在考察、论证的基础上，用SBSD批量给定器和质量流量计配套使用来代替椭圆齿轮设定器。

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Over 100 petitioners from across the country staged a mass demonstration at the capital's south railway station earlier in the week, the newspaper adds.

BBC: China media: Anger against Abe

The Black Watch supporters - who are also part of the Save The Scottish Regimentsw Campaign - plan to stage a mass demonstration against government plans in Dundee on 23 October.

BBC: NEWS | UK | Scotland | Councils rally to defend regiment

The proximate cause of last Friday's mass demonstration was what the so-called Twitter and Facebook revolutionaries consider the military's slowness to respond to their demand for ousted president Hosni Mubarak's head on a platter.

CENTERFORSECURITYPOLICY: The real Egyptian revolution