Txoj hauv kev los txo qis-ntsaws tam sim no
Txhawm rau kom txo qhov tsis muaj qhov nrawm tam sim no, nws yog qhov tseem ceeb tshaj los pib nrog cov tub ntxhais hlau ntawm qhov hloov pauv
1. Txhim kho qhov zoo ntawm silicon steel sheet.
2. Txhim kho cov qauv hlau tub ntxhais.
3. Hloov lub hwj huam hloov txheej txheem