沙砾覆于铁质土层与砂砾层之上.Gravelly - sand over an iron - pan and gravel layer.小石头、砂砾层也可用来做隔绝层,以保持水分,降低土壤的温度.Pebbles and gravel also insulate the soil to keep surface temperatures low and preserve water.古河谷的边缘地带,往往缺失底部的河床相砂砾层.The ed...
Reviewing courts were among the most active proponents of hybrid rulemaking procedures.复审法院是最积极的混合型规则制定程序的建议者.Proponents of such opinions were arrested as'traitors.'提倡这种主张的人马上作为“卖国贼 ” 逮捕起来.There are certain adv...