Nrhiav ib tus neeg muag khoom txhim khu kev qha rau koj daim ntawv thov casting thiab forging? Saib tsis muaj ntxiv dua li Hanspire, lub tuam txhab ua lag luam hauv kev lag luam. Nrog cov ntaub ntawv pov thawj ntawm kev xa cov khoom zoo
Ntim tau zoo heev, nthuav qhia rau lub zog. Tus neeg muag khoom muaj npe nrov heev. Kev xa khoom ceev kuj ceev heev. Tus nqi pheej yig dua li lwm lub tsev.