Daim ntawv thov: Xauv Hloov Chaw, Ntse Yuam Sij
Qhov tseem ceeb ntawm daim ntawv thov: Kev tsim cov tshuab loj, kev sib txuam siab ntau, ua cov txheej txheem tsim khoom luv luv, txo tus nqi, ua kom zoo nkauj ntawm lub ntsej muag, cov yam ntxwv lub zog ruaj khov, siab corrosion

Daim ntawv thov: Cov Khoom Siv Hluav Taws Xob
Qhov tseem ceeb ntawm daim ntawv thov: Qhov ntau lawm pawg loj yog ruaj khov, tus nqi qis dua li kev lag luam ib txwm muaj