Putting this material on roofs can help clean up smoggy air https://t.co/5UeGI71Sis https://t.co/l9AhfOga3Z

Putting this material on roofs can help clean up smoggy air https://t.co/5UeGI71Sis pic.twitter.com/l9AhfOga3Z

— de symbol (@desymbol) November 29, 2018

from Twitter https://twitter.com/desymbol

November 29, 2018 at 07:37PM