Tsis muaj teeb meem li cas koj xav siv cov yas dhos no, nws cov duab sau zoo yuav ua kom nws ruaj khov. Peb ntxiv qhov nyob rau hauv cov footpads kom cov neeg siv los kho tus tuav rau hauv av. Ua kev siv ntau qhov chaw ntsug rau ib daim hneev me me, kev ua tau zoo hauv kev txhim kho qhov hnyav hauv cheeb tsam kev ua tau zoo thiab cov tsos.
