COVID-19 spreads through patients’exhalation droplets,hence a comprehensive understanding of muco-saliva fragmentation provides crucial insight.This paper scrutinizes a study of the breakup of mimic of contagious viscoelastic exhalation fluid,conducted by MIT researchers:“Visualization of sneeze ejecta:steps of fluid fragmentation leading to respiratory droplets”,in which the authors profoundly contributed to the understanding of hazardous sneeze ejecta caused by sneezing.In this article,some of their nicely incorporated experimental methods and break through will be described and analyzed with the integration of fluid dynamics.