ahlam1399
04-17-2017, 08:29 PM
Scientists at the University of California, Berkeley have figured out why shoelaces seem to come untied at the worst moments, like when you're running.
أكثر... (http://www.npr.org/sections/health-shots/2017/04/17/523636317/untangling-the-mystery-of-why-shoelaces-come-untied?utm_medium=RSS&utm_campaign=news)
أكثر... (http://www.npr.org/sections/health-shots/2017/04/17/523636317/untangling-the-mystery-of-why-shoelaces-come-untied?utm_medium=RSS&utm_campaign=news)