Hom ntaub ntawv txuas nrog rau kev lis kev cai tshaj tawm: 1. Ntshuam thiab xa tawm cov ntaub ntawv ua lag luam, ntawm no hu ua cov ntaub ntawv xa tawm thiab xa tawm cov ntaub ntawv lag luam, xws li cov ntawv cog lus, cov ntawv xa nyiaj, cov ntawv ntim khoom, cov nqi thauj khoom, kev tuav pov hwm txoj cai, ntawv qiv nyiaj thiab lwm yam ntaub ntawv muab los ntawm cov neeg siv khoom. ib...
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