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
공장폐기물은 환경에 큰 영향을 미칠 수 있다.gongjangpaegimul-eun hwan-gyeong-e keun yeonghyang-eul michil su itda.Industrial waste can have a significant impact on the environment.