The crushed stone cement base is a semi-rigid surface structure adopted widely at present.

碎石基层是目前被广泛采用的半刚性路面结构。

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The MM600 is double-sided mat designed with foundation of a solid piece of 3mm thick aircraft-grade aluminum to provide a flatter, more rigid surface and no-slip rubber corners to minimize slippage during frenzied gaming sessions.

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According to tectonic theory, the surface of the Earth is made up of a patchwork of massive rigid plates, about 80km (50 miles) thick, which float in slow motion on top of the Earth's hot, pliable interior.

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