Cov rooj zaum zoo li yooj yim, tiam sis kev tsim khoom tsis yog yooj yim, nws tsuas yog muaj cov txheej txheem hauv qab no: thawb, vuam thiab tha xim ntawm lub rooj zaum, ua thiab xa cov khoom siv tom qab, ua daim npog ntsej muag thiab ntaub xaws, zoo li tag nrho lub rooj sib txoos kawg.
Zuag qhia tag nrho cov txheej txheem muaj nyob hauv daim duab:
