Nov yog yam tshiab ntawm kev hloov xim tsom iav. Cov iav hloov xim tuaj yeem hloov pauv nrog kev hloov pauv ntawm ultraviolet rays thiab kub hauv ib puag ncig, yog li tiv thaiv peb lub qhov muag.
Thaum caij tsheb sab nraud, nws yuav ua rau muaj kab mob hauv qhov muag, thiab hnav tsom iav hloov xim tuaj yeem tiv thaiv kab mob ultraviolet nkag los ntawm peb lub iav, thiab tuaj yeem tiv thaiv qhov muag, nkag siab zoo tiv thaiv lub qhov muag, thiab muab kev pom zoo rau lub qhov muag.
Xyuas
Muaj cov kev xyuas tsis tau.