It's an automatic reflex for many of us: obediently tapping a few times on a can of beer or soda to stop it from frothing over.
원문출처 : https://www.cnn.com/2019/12/12/world/beer-can-tapping-frothing-intl-scli-scn/index.html
원문출처 : https://www.cnn.com/2019/12/12/world/beer-can-tapping-frothing-intl-scli-scn/index.html