Dab tsi yog plaster siv rau, thiab vim li cas nws tseem ceeb? Plaster yog ntau yam khoom siv hauv tsev uas tau siv ntau pua xyoo hauv kev tsim kho thiab kho kom zoo nkauj. Nws muaj kev sib xyaw ntawm gypsum, txiv qaub, xuab zeb, thiab dej, uas yog siv los ua cov tshuaj pleev ib ce rau phab ntsa, qab nthab, thiab lwm qhov chaw. ...
Nyeem ntxiv