View full lesson: https://ed.ted.com/lessons/when-is-water-safe-to-drink-mia-nacamulli Water is refreshing, hydrating, and invaluable to your survival. But clean water remains a precious and often scarce commodity – […]
http://www.ted.com Too much of the world lacks access to clean drinking water. Engineer Michael Pritchard did something about it — inventing the portable Lifesaver […]