Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
이 연소로는 고온에서 금속을 녹이는 데 사용됩니다.i yeonso-ro-neun gooneseo geumsogeul nogineun de sayongdoemnida.This combustion furnace is used to melt metals at high temperatures.