What goes up and down stairs without moving?

Give it food and it will live; give it water and it will die. What am I?

I run, yet I have no legs. What am I?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

Which is correct to say, "The yolk of the egg are white?" or "The yolk of the egg is white?"

What do you serve that you can't eat?

What kind of room has no windows or doors?

I look at you, you look at me, I raise my right, you raise your left. What is it?

The more you take the more you leave behind. What am I?

Take one out and scratch my head, I am now black but once was red. What am I?

What can go up and come down without moving?