Cov neeg feem coob paub tias paj rwb yog ib qho ntawm cov ntaub ntawv qub tshaj plaws hauv xyoo caum. Yog li no, xav txog kev tiv thaiv ib puag ncig ntawm cov paj rwb, paj rwb yog cov khoom zoo tshaj plaws rau kev ua hnab piv nrog cov yas.