Answer:
It's been around for millions of years, but is never more than a month old. What is it?
I'm white, I'm round, but not always around. Sometimes you see me, sometimes you don't.
It happens when something has been cut with H2O.
I am black when I am clean and white when I am dirty?
Two brothers we are, great burdens we bear. All day we are bitterly pressed. Yet this I will say, we are full all the day, and empty when go to rest.
What did the piece of wood say when he saw the screwdriver and screws approaching?