Cov ntaub ntawv tshwj xeeb
Cov khoom no muaj kev luam tawm zoo heev, cov xim tsis sib xws, thiab cov teebmeem pom kev zoo, ua rau cov ntawv tseem ceeb heev. Nws yog ib hom ntawv uas, thaum raug tshav ntuj, qhia txog lub teeb xim thiab hloov lub teeb ultraviolet mus rau pom lub teeb, uas yog tom qab ntawd rov qab los. Yog li ntawd, nws muaj xim ci dua li cov ntawv nplaum zoo tib yam. 
