Cov khoom zoo li cas yuav tsum tau txhaj cov khoom pwm tuaj? Qhov kev xaiv ntawm cov khoom xyaw?
Lub cev muaj pwm thiab cov ntaub ntawv kev sib raug zoo zoo heev, hauv cov khoom siv yas yas, kev ua tau zoo ntawm tus cwj pwm ua haujlwm tseem ceeb heev, yog li qhov tseem ceeb xav txog hom kev xaiv raw li no.Thaum yuav tsum tau ua raws li cov cai ntawm kev siv cov yas, lub ntsiab lossis txawm tsim ntawm cov pwm yog tswj los ntawm cov khoom siv hauv kev lag luam, xws li cov pwm tsim yuav tsum xav txog qhov kev txav ntawm cov yas molding shrinkage piv, qhov kub, thiab lwm yam.