stream bottom soil是什么意思

用法例句

In deriving 102 surface samples from farmland soil of Henan within the territory,it has been analyzed for element contents of 8 kind heavy metal,such as Cr,Zn,Cu,Pb, Ni.

结果表明:河南农田土壤中除Cr偶有超出我国《土壤环境质量标准》(GB 15618—1995)二级标准的土样外,其他项目均不超标,重金属污染由高到低排序为Cr>Zn>Ni>Cd>Hg>Cu>Pb>As。