uPVC Cov kav dej

Cov khoom lag luam uas pabcuam kev noj qab haus huv ntawm cov pejxeem.Raws li WHO, cov khoom lag luam no yuav tsum muaj "txhua lub sijhawm, nyob rau hauv cov nyiaj txaus hauv cov ntawv tsim nyog, nrog cov ntaub ntawv pov thawj zoo thiab tsim nyog, thiab ntawm tus nqi uas tus neeg thiab cov zej zog muaj peev xwm them taus".