Tsw muaj ib yaam kev swm sab twg yuav tshwm lug raug mej dhau tej kws txeev tshwm lug raug ib tsoom tuabneeg lawd. Vaajtswv yog tug kws peb tso sab tau, mas nwg yuav tsw ca mej raug kev swm sab dhau le kws mej thev tsw taug, tassws thaus raug kev swm sab nwg yuav qheb kev rua mej dim sub mej txhad le thev taug.