These layers are called strata and a single layer is called a stratum.

这些岩层被称作地层（strata）（stratum的复数形式）， 单个岩层称为stratum。

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"When we are in the bath and we have been there for a while the stratum corneum [outer] layer of our skin expands," says Evans. "This causes wrinkles and means our fingerprints will be enlarged also."

“泡浴时，我们皮肤的角质层(外层)会有那么一刻时间扩张开来，”埃文斯说，“这导致我们的指纹出现皱纹或者扩张的情况。”

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"The new soccer centre emerges from the park's artificial topography as a layer of mineral stratum recalling the geological nature of the site," said the architects.

“新足球中心从该公园的人造地形中脱胎而出，作为一层矿物地貌以回忆场地的地质性质。”建筑师说。

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