Xyoo tsis ntev los no, qhov ua tau zoo thiab kev siv tshuab ntawm xaim saws tsim los ntawm cov tuam ntxhab tau tsim kho tsis tu ncua, thiab tau mus txog los yog ze rau qib siab ntawm cov khoom zoo sib xws. Kev txhim kho tas mus li qhov kev ua tau zoo ntawm cov hlua hlau, vim muaj kev siv dav dav los ntawm cov hlua muaj hlau zoo, tau daws qhov teeb meem ntawm kev tawg yooj yim ntawm cov xov hlau tau pom thiab txhim kho ncaj qha ntawm cov kav hlau.
Tam sim no, lub zog siab yas thiab roj hmab siv feem ntau, uas ua rau kev sib xyaw ntawm cov hlaws thiab cov kav hlau hlau muaj zog, daws cov teeb meem ntawm cov hlaws dai thiab channel cov hlaws, thiab zoo heev txhim kho qhov zoo ntawm cov hlau hlau. Lub tshuab xaim hluav taws xob tam sim no tau tsim ntau hom zeb tshuab, xws li marble mining hlua, granite mining hlua, ua ke cov hlau pom cov hlua thiab lwm yam khoom. Cov kev npaj txiav sib txawv tuaj yeem ua raws li qhov kev xav tau tshwj xeeb ntawm cov neeg siv khoom.
