Yuav ua li cas xaiv cov cutter hniav
Peb qhia koj seb yuav xaiv lub tshuab raj ntiv tes, tab sis feem ntau ntawm koj yuav tsis paub ntau txog kev txiav, yog li cia ua ntej kom meej li cas lub tshuab txiav: lub tshuab txiav yog siv cov cuab yeej siv rau ntau yam lag luam, uas yog siv los txiav ntawm ntau cov ntaub ntawv. Cov hniav yog ib feem tseem ceeb ntawm cov khoom siv no. Yog hais tias tus hniav xaiv los ntawm cutter yog tsis haum thiab tsis ntse, nws yuav twv yuav raug rau nws cov kev khiav hauj lwm. Tom ntej no, cia peb kawm seb yuav ua li cas xaiv ib txoj hau kev.
Xaiv cov phuam hniav. Ua ntej tshaj plaws, peb yuav tsum tau paub tseeb qhov koj xav ua nrog nws. Yog li ntawd, peb yuav tsum paub kom meej meej cov khoom, hardness thiab tuab ntawm cov khoom txiav. Peb yuav tsum tau tshawb xyuas qhov tseeb ntawm cov hniav uas peb xav tau xaiv raws li qhov tseeb qhov teeb meem, kom koj qhov kawg xaiv yuav pab tau rau koj txoj haujlwm. Tsis tas li ntawd, lub tshuab txiav tawm kuj muab faib ua ob sab - cov hniav thiab ib sab - ib sab. Ib sab khib nyiab tuaj yeem lav tau qhov khoom siv txiav cov khoom kom zoo tshaj plaws. Muab ob npaug rau ib sab yog tsim rau cov khoom muag muag, thiab lub neej ua haujlwm ntev. Hauv qhov no, peb yuav tsum txiav txim siab raws li peb tus kheej xav tau.
