Ob qhov khoom siv loj siv hauv lub thawv txawb lub tsev yog xim hlau daim hlau thiab cov ncej steel, ntxiv rau cov khoom siv me me txuas cov phaj, qhov rooj thiab qhov rais, iav kua nplaum, lub teeb raj, cov hloov hluav taws xob, thiab lwm yam. Kev tsim kho qhov chaw nyob lub thawv yog ib hom steel qauv board lub tsev. , thiab tam sim no ntau board ...
Nyeem ntxiv