Suetion devices are inadequate in gravels or very porous soils.吸水装置对砂砾或非常疏松的土壤是不适用的.They may form concentrated pockets in gravels.它们可能在砾石堆积物中形成富集的矿囊.Graves are a mix of gravels, clay and sand carried out by the river.它混合...
我们的历史教师总爱概括地讲, 从不详述任何史实.Our history teacher is always generalizing; he never deals with anything in detail.他概括地说了整个情况.He had put the whole situation in a nutshell.有必要概括地讲一下有关的高斯公式.It will be useful to summarize the relev...