Abstract Background The COVID-19 pandemic is adversely impacting modern human civilization. A global view using a systems science approach is necessary to recognize the close interactions between health of animals. humans and the environment. Discussion A model is developed initially by describing five sequential or parallel steps on how a RNA virus emerged from animals and became a p... https://www.diegojavierfares.com/mega-deal-Stanford-Fireplace-Mantel-Shelf-p6534-big-savings/