Late pool forming periods and the Tertiary undercompacted mudstone forming large area of pressure sealings are advantageous to the preservation of natural gas.
成藏期晚和第三系欠压实泥岩形成大面积的压力封盖，有利于天然气的保存。
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Article 27 The commodity inspection authorities may, when necessary, place commodity inspection marks or sealings on import and export commodities proved to be up to standard through inspection.
第二十七条商检机构根据需要，对检验合格的进出口商品，可以加施商检标志或者封识。
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Article 23. The commodity inspection authorities may, when necessary, place commodity inspection marks or sealings on import and export commodities proved to be up to standard through inspection.