a) Nrog pab tuav kom ruaj ntseg ntawm kev cob qhia txav
b) Kev hloov kho lub nraub qaum tuaj yeem ua tau raws li qhov xav tau ntawm cov neeg sib txawv.
c) Nrog rau daim ntawv hloov kho kom tau raws li qhov xav tau ntawm cov neeg sib txawv.
d) Nrog limiting mechanism kom muaj kev ruaj ntseg ntawm tus kws qhia.