Hniav disc, lub tuam txhab tsim hniav disc harrow, lemken fais fab harrow qhov chaw faib khoom

Tag nrho cov khoom yog ua los ntawm cov hlau boron zoo, tom qab forging thiab cua sov kho ua tiav, kom ntseeg tau tias cov khoom muaj zog txaus thiab hnav tsis kam. Cov khoom raug xa tawm mus rau Russia, Lithuania, Spain thiab lwm lub tebchaws, tom qab ntau qhov kev sim ua lag luam los ntawm cov neeg siv khoom, nws cov haujlwm ua haujlwm zoo yog thawj chav kawm.