All these rocks were formed naturally.

这些石头都是天然形成的。

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Natural Grand Buddha: formed naturally due to drop of water.

天然巨佛――由长年滴水自然形成。

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The notion of harnessing the power of electricity formed naturally has tantalized scientists for centuries.

几个世纪以来，如何驾驭这种自然形态电能的问题，一直困扰着科学家。

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When the mechanical properties of this new cartilage were tested, they showed that the regenerated cells were just as effective as the rabbit's naturally formed cartilage.

VOA: standard.2010.08.11

Butz said the six "ovens" formed naturally as a result of spherical deposits of quartz eroding out of the phyllite rock face.

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But they formed naturally, as they formed alliances with other like-minded politicians.

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They are formed by a naturally occurring family of tooth-specific proteins known as amelogenins.

BBC: By BBC News Online Science Editor Dr David Whitehouse