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
그는 실증주의자이기 때문에 과학적 방법을 중요하게 생각한다.geuneun siljeungjuuijaigideun geugwa hakjeok bangbeob-eul jungyohage saeng-gaghandan.He is a positivist, so he values scientific methods.