Cov khoom
Aoyin hlau kev lag luam muab ntau yam khoom siv txhuas. Peb cov khoom siv hauv kev tsim kho, kho kom zoo nkauj, tsheb, khoom siv hluav taws xob, tshuab, nkoj tsim, aerospace, khoom siv ua noj, ntim khoom, thiab lwm yam hauv 20 xyoo dhau los, peb cov khoom siv txhuas tau muag thoob plaws ntiaj teb nrog rau South America, North America, Europe, Middle East, Southeast Asia thiab Africa. Hu rau peb kom paub meej tias koj daim ntawv thov hu rau qhov twg thiab peb tuaj yeem ua cov txheej txheem koj xav tau.
