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
지진계는 지진의 강도를 측정하는 데 사용됩니다.jijin-gye-neun jijin-ui gangdo-reul cheugjeonghaneun de sayongdoemnida.A seismometer is used to measure the intensity of earthquakes.