Dema ndiyo nzira yakajairika yesimbi kupisa kurapwa.Nheyo yacho ndeyekugadzira firimu reoxide pane simbi pamusoro kuti iparadzanise mhepo uye kuwana kudzivirira ngura.Blackening inzira yakajairika yesimbi kupisa kurapwa.Nheyo yacho ndeyekugadzira firimu reoxide pane simbi pamusoro kuti iparadzanise mhepo uye kuwana kudzivirira ngura