Sai los tom qab, txhua tus yuav tsum kho lawv chav dej. Lub ntsiab tseem ceeb yog hloov cov vuas thiab da dej. Txawm li cas los xij, tom qab cov txheej txheem kev teeb tsa, qee qhov sib txawv ntawm lawv. Qhov no yog qhov chaw tseem ceeb rau kev loj hlob ntawm pwm, plaque thiab av tsub zuj zuj. Txhawm rau kom tsis txhob muaj qhov xwm txheej zoo li no thiab tiv thaiv qhov tshwm sim ntawm pwm, kev sib khi zoo ntawm cov pob qij txha yuav tsum tau ua. Tab sis yuav ua li cas ua kom cov pob zeb sib txuas ntawm cov vuas rau da dej kom raug? Xav txog cov txheej txheem nrov tshaj plaws