Tsis tuaj yeem siv ob zaug.
Cov ntsia thawv daim tseem yuav tsum tau polished thiab polished thaum ua cov ntsia thawv kos duab, yog li lawv tau siv thaum thawj tus ntsia thawv kos duab tiav. Yog tias koj xav ua tus ntsia thawv kos duab thib ob, koj yuav tsum tshem tawm thawj tus ntsia thawv kos duab. Thaum tshem tawm cov ntsia thawv kos duab, cov ntsia hlau daim yuav raug rhuav tshem, uas yuav ua rau tus ntsia thawv kos duab thib ob ua tsis tau yooj yim. Yog li ntawd, feem ntau hais lus, cov ntsia hlau daim yog cov khoom pov tseg.
