周围介质污染
environmental contamination
岩质围岩亚级分级
rocky surrounding rock sub-classification
导体-介质周期薄膜
conductor-dielectric periodic thin films
拱涵周围土体
earth surrounding arch culvert
介质周期结构
Dielectric periodic structure
dielectric periodic sturcture
深厚围岩(土)
Classroom seat arrangement