Peb nkag siab tias cov kua dej txiav muaj cov khoom tseem ceeb xws li cua txias, lubrication, tiv thaiv xeb, ntxuav, thiab lwm yam. Cov khoom no tau ua tiav los ntawm ntau yam khoom ntxiv uas muaj cov haujlwm sib txawv. Qee cov additives muab lubrication, qee qhov tiv thaiv xeb, thaum lwm tus muaj bactericidal thiab ...
Nyeem ntxiv