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 자계는 생명체에 큰 영향을 미친다.jiguui jagyeun saengmyeongche-e keun yeonghyang-eul michinda.The Earth's magnetic field has a significant impact on living organisms.