Permafrost soil
美英
        - un.永冻土壤
 - 网络多年冻土
 
Permafrost soilPermafrost soil
多年冻土
多年冻土,Permafrost,音标,读音,翻译,英文例... ... ) permafrost soil 多年冻土 ) perennial frozen earth 多年冻土 ... 
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        Discussion on Buried Seat of Thermal Insulation Material for Subgrade Engineering in Permafrost Soil Zone
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