shoelaces

American scientists find the real reason why the shoelaces are always slipping away, no matter how tight the user is.

Everyone was very hard when they were able to tie the shoelaces. Velcro glued shoes are favored by many parents due to their convenience, just pulling it out and sticking it in is

It seems useless, but two small holes on the sneakers have great use, but few people know.

When more and more buttons are tied, the shoelace is easier to slip, not everyone understands why.