ba salam be hame mohandesiine madan...az jahaty ke gerayesham estekhrtaje,,1 soale faravary daram,,,
1madane fluorine hast,ke az jahaty ke havazegii sang balast taghriban khord shodeast,,,va grade ideal baraye flourin 97% hastesh,,,vali grade fluorine in madan 50% hast,,,soalam injast ke aval...