3 questions, each answered from published authorities with the sources listed.
Photo by DoctorJoeE, via Wikimedia Commons, CC BY-SA 4.0. Source: https://commons.wikimedia.org/wiki/File:Okavango_Delta.jpg. License: https://creativecommons.org/licenses/by-sa/4.0/AuthorDoctorJoeE · CC BY-SA 4.0File source