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
지구의 생물계는 다양한 생물들로 구성되어 있습니다.jiguui saengmul-gyeun da-yanghan saengmuldeullo guseongdoeeo itsseumnida.The biosphere of the Earth is composed of various organisms.