Answer:
What does everyone know how to open but not how to close?
What can answer in any language? What can speak without a mouth? What can sing without an ear?
You will find me with four legs, but no hair. People ride me for hours, but I don't go anywhere without needing to be tugged. Jerked or turned on, I always manage to be ready for work.
It is a path of cow juice spread across the sky but cannot be seen by the naked eye
What goes up when the rain comes down?
My days are numbered. What am I?