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
결정레이저는 고출력 레이저를 생성하는 데 사용됩니다.gyeoljeong leijeoneun gochulyeok leijeoreul saengsanghaneun de sayongdoemnida.The crystal laser is used to generate high-power lasers.