1. Cov ntaub ntawv iav muaj qhov sib txeeb zoo, uas tuaj yeem tiv thaiv qhov cuam tshuam ntawm oxygen thiab lwm cov roj cua hauv cov txheej txheem sab hauv, thiab tiv thaiv cov khoom ntaws ntawm cov txheej txheem puab ntawm volatilizing rau hauv qhov chaw.
2. Cov iav fwj siv tau ntau dua los txo cov nqi ntim khoom.
3. Cov iav tuaj yeem yooj yim hloov nws cov xim thiab daim ntawv kaj.
4. Cov iav fwj muaj kev ruaj ntseg thiab ua kom huv si. Lawv muaj kev txhim khu muaj zog thiab acid acid. Lawv tsim nyog rau ntim acidic (xws li zaub, kua txiv, dej haus, thiab lwm yam).
5. Tsis tas li ntawd, raws li cov iav fwj yeej tsim rau kev siv cov kab ua kom tsis raug sau ntau, kev txhim kho ntawm cov iav fwj siv lub tshuab fais fab thiab cov khoom siv kuj yog qub, thiab siv cov iav fwj rau cov txiv hmab txiv ntoo thiab kua txiv hmab txiv ntoo zoo nyob rau hauv Suav teb.
