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
중간축은 기계의 동력을 전달하는 중요한 부품입니다.jungganchugeun gigyeui donglyeogeul jeondalhaneun jungyohan bupumimnida.The countershaft is an important component that transmits power in a machine.