Ntau tshaj 20 xyoo abrasive khoom raug tsim nyob rau hauv Suav teb, peb paub txog peb cov khoom lag luam raw khoom zoo, thiab tseem tswj cov khoom siv raw zoo kom paub meej cov khoom zoo.

Advanced German cov cuab yeej tsim khoom, cov txheej txheem ntau lawm los xyuas kom meej cov khoom tsim nyog tus nqi txog li 99 feem pua.

Peb pab pawg neeg ua haujlwm tau cog lus los tsim cov khoom tshiab los muab cov kev daws teeb meem kev lag luam sib txawv, thiab txhawb cov neeg siv khoom kom nthuav dav cov khoom lag luam los txhim kho kev lag luam kev sib tw.

Cov cuab yeej ntsuas qib siab, cov qauv ntsuas nruj thiab kev tswj hwm nruj, dhau 13 xyoos ntawm kev paub txog kev ua haujlwm abrasives cov txheej txheem los ntawm cov txheej txheem los ntawm cov khoom siv raw mus rau cov khoom tiav kom ntseeg tau tias txhua cov khoom xa tuaj yog tsim nyog ua ntej xa.

Peb pab neeg ua haujlwm tau txais kev cob qhia zoo, cov neeg siv khoom xav tau, thiab muab cov kev daws teeb meem kom tau raws li cov neeg siv khoom xav tau.

Peb them nyiaj mus ntsib cov neeg siv khoom thiab tuaj koom hauv tsev thiab hauv kev nthuav tawm los ua kev tshawb fawb txog kev lag luam kom ntseeg tau cov neeg siv khoom zoo dua, thiab txhawb cov neeg siv khoom tsim kev lag luam thiab tau txais kev lag luam ntau dua.