DONGSHAO yog ib lub chaw tsim khoom muaj koob npe nrov hauv Suav teb thiab cov chaw muag khoom nrog ntau xyoo ntawm kev paub tshwj xeeb hauv Flat Washer ntau lawm. Peb vam tias yuav tsim kev lag luam kev sib raug zoo nrog koj.