Answer:
I have a small hill with seven holes.
In the sun I like to play; in the rain I goes away; walk or run I always follow; in the mud I always wallow.
I am an instrument capable of making numerous sounds but cannot be touched or seen. What am I?
I keep growing and am practically indestructible. I get eaten, but always come back. I survive cold and lie everywhere. You see me everyday. What am I?
Many people own a copy of me. Without me the world would fall.
You can always see it, but it's too far away to touch. Mountains rest on it, and at sea it surrounds you. What is it?