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
생명계는 지구의 모든 생물체가 살고 있는 환경입니다.saengmyeonggye-neun jigu-ui modeun saengmulche-ga salgo itneun hwangyeong-imnida.The biosphere is the environment where all living organisms on Earth reside.