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
석유따위는 환경에 해로운 영향을 미칠 수 있다.seogyu ttawi-neun hwan-gyeong-e haeroun yeonghyang-eul michil su itda.Petroleum and similar substances can have harmful effects on the environment.