У вашего броузера проблема в совместимости с HTML5
Part 3 in an 8 part lecture on skeletal muscle in a flipped Human Anatomy course taught by Wendy Riggs. CC-BY. Watch the whole lecture (all 8 videos) by going to the PLAYLIST: https://www.youtube.com/playlist?list=PL5GRRRmaGVqULgUPJAZLzp5SWFiR4Xd3I