短語詞組短語bearing g stratum 承重層water -bearing sand stratum 含水砂層oil bearing stratum 含油地層poor bearing stratum 低承載性地層siltrock bearing stratum 泥砂巖持力層determing of bearing stratum 持力層確定ore bearing stratum 含鑛地層ore -bearing stratum 鑛地層 返回 bearing stratum