1. Nws yog ib qho tsim nyog yuav tsum paub meej tias hom kev kos duab tau txais, seb nws yog ib qho kev sib dhos, kos duab kos duab, daim duab kos duab, lossis ib feem ntawm daim duab, BOM lub rooj.Ntau hom kev kos duab yuav tsum tau nthuav tawm cov ntaub ntawv sib txawv thiab ua kom pom tseeb;- Rau mechanical txheej txheem ...
Nyeem ntxiv