double-covering-layer的意思|示意

美 / / 英 / /

双覆层 ... concrete covering-layer 混凝土覆盖层 double-covering-layer 双覆层 covering soil layer inside levee 堤内压盖 ...

The best is double plastic membrane cover, although more expensive than plastic covering layer higher, but the heat preservation effect is good.

最好是覆盖双层塑膜，虽然成本比单层塑膜覆盖高些，但保温效果较好。