Mfundo yogwirira ntchito:Wowuzira amayendetsa gudumu lamphepo kudzera mu injini ya petulo yokhala ndi mikwingwirima iwiri kuti apange mpweya wothamanga kwambiri kenako ndikuzimitsa moto ndi zina.Izo ntchito kuyeretsa pamaso woonda slurry kusindikiza wosanjikiza pa khwalala.