Peb tab tom ntxiv kev faib tshiab Yas txhaj tshuaj molding, txheej txheem kev tsim khoom uas tau hloov pauv kev tsim khoom ntawm ntau yam khoom hauv kev lag luam sib txawv. Los ntawm kev lag luam tsheb thiab kev kho mob mus rau cov khoom siv hluav taws xob thiab cov khoom siv, kev txhaj tshuaj molding tau dhau los ua ib txoj hauv kev nrov rau kev tsim cov khoom zoo thiab cov nqi tsim nyog los daws cov teeb meem ntawm cov neeg siv khoom.