Lub rooj tsav xwm ceev yog tsim los ntawm cov khoom siv hluav taws xob thiab cov khoom siv fiber ntau, tom qab ntawd ntxiv cov nplaum, los ntawm cov txheej txheem kub kub ua ke, thiab cov khoom siv ntoo yog siv cov khoom siv fiber ntau, txawm tias qee cov khoom siv tib yam, tab sis tseem muaj qee qhov sib txawv, tsis txhob ' tsis paub tias koj tab tom xaiv lub plank...
Nyeem ntxiv