<prompt> Pedzisa mutsara unotevera: Broad Street yaizivikanwa zvikuru senzvimbo  <response>: Kupararira kwecholera muna 1854. Dr. John Snow vakatevera kupararira kwechirwere ichi kusvika papombi yemvura yomunharaunda iri mumugwagwa, uye vakaidzima. Nguva iyi isati yasvika, chirwere chacho chaifungidzirwa zvikuru kuti chinokonzerwa nemiasma inofambiswa nemhepo; zvakawanikwa naSnow zvakaratidza kuti chinoparadzirwa nemvura. 