26:06Learning
From the PhD Lab: How do biofilms help keep bacteria alive? - with Josh Horton
The Royal Institution
Everyday Grammar: While vs. Whereas
From the creator
Originally published at - http://learningenglish.voanews.com/a/everyday-grammar-while-vs-whereas/3639280.html
Published 2017-01-29 · Watch on YouTube ↗
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