Peb tau tsim cov kab ntau lawm iav rwb thaiv tsev uas muaj qhov sov thiab qhov ntsug kom tau raws li qhov xav tau ntawm cov neeg siv khoom sib txawv. Cov tshuab no siv tau los ua cov iav rwb thaiv tsev uas muaj qhov sov thiab cov iav rwb thaiv tsev uas muaj qhov sov thiab qhov dav.