Answer:
I am an activity dogs are very good at when a ball is thrown.
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
As a state in the USA, I am round on both sides and high in the middle. What am I?
A hole in a pole. Though I fill a hole in white I'm used more by the day and less by the night
What can go up a chimney down but canβt go down a chimney up?
What begins and has no end? What is the ending of all that begins?