Lub raj mis cawv yog lub thawv ntim keeb kwm, lub raj mis manufacturers hauv kev tsim cov raj mis cawv, yuav muab qee cov hmoov txhuas rau hauv, uas tuaj yeem txhim kho cov iav fwj zoo, tab sis cov hmoov txhuas yog cov khoom tsis zoo rau tib neeg lub cev, yog li peb yuav ua li cas thiaj kuaj tau. seb cov iav fwj puas muaj txhuas?
1. Mloog lub suab. Cov iav fwj uas muaj cov hlau lead emit suab hlau, thiab iav fwj uas tsis muaj hlau lead emit suab zoo.
2. Saib xim. Cov iav iav tsis muaj txhuas muaj cov khoom zoo dua li cov iav fwj uas muaj cov hmoov txhuas, xws li qee cov khoom dai ntawm ntau cov duab, cov iav siv lead ua iav, thiab lwm yam yog ua los ntawm cov iav lead.
3. Ntsuas qhov hnyav. Cov khoom siv iav lead yog me ntsis tuab dua li cov iav tsis muaj hlau lead.
4. Saib qhov tawv. Piv nrog cov iav tsis muaj hlau lead, cov iav tsis muaj hlau lead yog cov tawv tawv dua thiab muaj kev cuam tshuam.
