Yog tias muaj cov kua qaub pph fittings pop

Puas yog koj cov kav dej nkag rau cov kua qaub thiab cua sov? Pollings nyob ntawm no los pab!
Resistant rau cov kua qaub, alkalis, thiab qhov kub, lawv tuaj yeem ua cov kav dej kub thiab tshuaj lom neeg.