Answer:
Round as an apple, deep as a cup, and all the kings' horses can't fill it up. What is it?
In we go, out we go. All around and in a row. Always, always steady flow. When we'll stop, you'll never known. In we go, out we go.
Used left or right, I get to travel over cobblestone or gravel. Used up, I vie for sweet success, used down, I cause men great duress.
One by one we fall from heaven down into the depths of past, And our world is ever upturned so that yet some time we’ll last.
Runs smoother than any rhyme, loves to fall but cannot climb.
What did the piece of wood say when he saw the screwdriver and screws approaching?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?