Tus Kws Tshaj Lij Qhia Peb Cobalt yog ib qho silvery dawb hlau.cibalt tsis muaj kev cuam tshuam nrog saum chav kub 300 tawm rhuab hauv cov pa oxidation tsim?
Tuplus cov neeg ua haujlwm ua haujlwm txuas ntxiv yuav txuas ntxiv qhia koj txog kev paub ntawm kev cob qhia.
