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
현수선은 전선의 형태를 설명하는 데 사용됩니다.Hyeonsuseoneun jeonseonui hyeongtaereul seolmyeonghaneun de sayongdoemnida.The catenary is used to describe the shape of a suspended wire.