The Department of Defense<\/strong> first published \u201cChemtrails<\/strong>\u201d in 1990 as the title to a required chemistry course for new pilots attending the esteemed US Air Force Academy<\/strong>. The term \u201cchemtrails<\/strong>\u201d, and its implied meaning were eventually adopted by civilian and retired military observers to describe unusual<\/a> jet contrail emissions. (Oxford dictionary)
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