There's one mask guideline that hasn't changed throughout the pandemic -- you definitely should be wearing one.
원문출처 : https://www.cnn.com/2021/02/05/us/counterfeit-masks-how-to-spot-trnd/index.html
원문출처 : https://www.cnn.com/2021/02/05/us/counterfeit-masks-how-to-spot-trnd/index.html