Ivalve ye-DBB “yivalve enye enemigangatho emibini yokuhlala ethi, ikwindawo evaliweyo, ibonelele ngokutywina ngokuchasene noxinzelelo oluvela kuzo zombini iziphelo zevalvu, ngendlela yokukhupha umoya/yokufaka umngxuma phakathi kweendawo zokuhlala.