實驗表明,過濾器可以生產(chǎn)更安全的飲用水。

Hints:
Jeffrey Schwarz
Pennsylvania
Jeff Schwarz
AmeriCorps
Tests have shown that the filter produces safe drinking water. On a good day, Jeffrey Schwarz says the studio in the library can produce?20 filters. To make one, clay is mixed with a material that burns. It could be sawdust or agricultural waste like grain hulls, cocoa or coffee shells. Pine ne…
整理中......