sand-filledCOCA¹¹³³⁰⁵BNC¹¹⁴⁰²⁴⁺⁵Economist⁵³⁵⁸¹⁺¹ 基本例句 adj.填满泥沙的；填砂的；n.填砂的 In the present study, we developed a flow- through system of sand-filled micro Bio-Spin columns to determine the distribution of extracellular DNA in sand and employed E. 为了研究 DNA释放进沙之后的分布及转化活性，建立了流过式微型离心沙柱。 cnki