Of the ones that do up the strap, about half have them so loose that they can put-on and remove the helmet without unbuckling.

带子扣上的人又有一半的带子太松，以致于不用动扣子就可以把安全帽戴上或取下。

youdao

Of the ones that do up the strap, about half have them so loose that they can put-on and remove the helmet without unbuckling.

带子扣上的人又有一半的带子太松，以致于不用动扣子就可以把安全帽戴上或取下。

youdao