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
휘발성이 높은 화학 물질은 안전하게 보관해야 합니다.hwibalseongi nop-eun hwahak muljil-eun anjeonhage bogwanhaeya hamnida.Chemical substances with high volatility must be stored safely.