Okokuqala, xa ufaka i-valve yensimbi engenasici, qaphela ukuba ungabetheli iivalve ezenziwe ngezinto ezinqabileyo;Emva koko, ngaphambi kokufakwa, jonga i-valve yensimbi engenasici, khangela inkcazo kunye nemodeli, kwaye ukhangele ukuba i-valve yonakaliswe;Okwesibini, nikela ingqalelo ukucoca umbhobho co...
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