-
Coal Mining Kev Lag Luam
Hauv kev lag luam thee mining, cov khoom siv lim dej tuaj yeem lim cov khoom zoo hauv huab cua lossis cov kua dej, cov khoom muaj kuab paug, thiab cov hmoov uas tsim los ntawm cov khoom siv hnav thiab tsim kua muag, kom ntseeg tau tias cov kua dej huv lossis cua.Qhov no tuaj yeem ua tau zoo e...Nyeem ntxiv
