What Am I Riddles

Question: Hollow of water, tongue of wood, skin of stone, long I've stood. What am I?

Question: Shake me and I'll do what you want,
but first you have to pull me from the ground.
I'm on the tip of your tongue and over your shoulder.

What am I?

Question: You find me behind the stars; or in a sixth, seventh, or third.
It takes something round, a computer, and me to make pie.
I am bigger than anything you can think of.

What am I?

Question: What goes up when the rain goes down?

Question: While you were folding a letter I got you.
Usually you will do whatever it takes to avoid me,
but now you can't help but find me.

What am I?