Qhov kev tshaj tawm ntawm cov ntawv luam tawm tshiab thiab nrov dua hauv khw, tshwj xeeb tshaj yog Hoobkas ib txwm siv rau kub stamping rau khau.
Tsis tas li, tshiab tuaj txog fusing tshuab rau khau, muaj cua txias ua haujlwm tom qab lub tshuab fusing.