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
복사계를 사용하여 태양의 복사 에너지를 측정할 수 있습니다.Boksagye-reul sayonghayeo taeyang-ui boksah enerjireul cheugjeonghal su itsseumnida.You can use a radiometer to measure the solar radiation energy.