Cov qauv hlau zoo, galvanized nto, pleev xim piano rau hauv qab phaj, ruaj khov thiab muaj peev xwm nqa tau.
Fuma lub log hloov kho tshiab yog kev sib xyaw ua ke, hloov tau yooj yim hauv deformation, siab hnav tsis kam, loj hauv kev thauj khoom, siab ruaj khov, tsis sib xws hauv cov kabmob muaj peev xwm thiab dav hauv daim ntawv thov ntau yam.
Kev Siv: Cov log no tsim nyog rau cov khoom siv tshuab, khoom siv hluav taws xob, khoom siv kho mob, khoos phis tawj, rooj tog zaum, cov cuab yeej siv tshuab, thiab lwm yam.