Hellow guys, Welcome to my website, and you are watching 델타 변이 확산...전 세계 4차 대유행 현실화 / YTN 사이언스. and this vIdeo is uploaded by YTN 사이언스 투데이 at 2021-07-25T20:13:44-07:00. We are pramote this video only for entertainment and educational perpose only. So, I hop you like our website.