首次提出了新型煤——砂双层均匀滤料滤池。

A new type of uniform dual media anthracite - sand filter is firstly proposed in this paper.

youdao

首次提出了新型煤——砂双层均匀滤料滤池。

A new type of uniform dual media anthracite - sand filter is firstly proposed in this paper.

youdao