Ndili zimachitika m'mabuku opanga mankhwala oyambira mwana , amatha kupereka zowonjezera . pamakina zomwe ancythether ndi zaka zambiri Kuphatikiza pa mndandanda wazogulitsa pansipa, mutha kusinthanso zomwe mumapanga makina anu enieni a mankhwalawa molingana ndi zosowa zanu zapadera.