Ukumakwa Kwezisetshenziswa zikagesi eziphephile ngaphakathi

Omaka bezinto zokusebenza eziphephile yizo: ia, ib, noma ic.

Izinga Lokuphepha	Ileveli Yokuphepha Yangaphakathi
Okujwayelekile	IA,IB,IC

Izinga eliphakeme kakhulu lokuvikela ukuqhuma liboniswa ngu-ia, kuyilapho okuphansi kuchazwa ngu-ic.