what is always going but never gets anywhere?

what is always going but never gets anywhere? Where is always going but never gets anywhere? what is always going but never get anywhere? what is always going butnever gets anywhere? what is always going but never gets angwhere? What never asks questions but always gets answers? 谜语：What never asks any questions but always gets answers? What't never asks any questions but always gets answers? what never ask questions but always gets answers? I always fly high in the sky,but l never get anywhere.what a 脑筋急转弯：what never asks any questions but always gets answers? what is it that is always coming but never arrives?