1, tej zaum yuav yog vim kev siv dua thinner, tshwj xeeb tshaj yog cov thinner thiab number case dolubility yog tsis zoo, ua rau infiltration ntawm xim.
2, tej zaum yuav yog vim kev siv tus kav dej hauv qhov zas - tshwm sim, nws tuaj yeem hais tau tias kev siv nrog cov pigocation tshwm sim los ntawm kev sib txawv.
3, tej zaum yuav yog vim muaj luam tawm thiab cov ntawv sau hais txog qhov tshwm sim, yog li tsis txhob txhawj xeeb tshaj plaws, ntev npaum li cov txheej txheem dav dav.
