Cov khoom siv ntau lawm
1. Cov khoom siv
Peb muaj 35 cov khoom pib-tshuab koom nrog 14 tshuab tsim 107 txiav disc.
2. Hardening
3 Tunnel kilns thiab 5 lub thawv rauv ua kom lub sijhawm tawv ntawm cov khoom
3. Cov khoom siv kuaj
Los ntawm kev soj ntsuam cov khoom siv raw mus rau cov khoom tiav kuaj kom paub meej cov khoom zoo
