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
열단의 측정은 에너지 효율성을 평가하는 데 중요합니다.yeoldanui cheugjeong-eun eneoji hyoyulseong-eul pyeongga-haneun de jungyohamnida.The measurement of the heat unit is important for evaluating energy efficiency.