Answer:
Man's most important invention.
A blue man lives in the blue house. A red man lives in the red house. Who lives in the white house?
What can go up but never come down?
Why is 6 afraid of 7?
What is something that can go up quite easily, but is not as easy to bring back down?
What did the piece of wood say when he saw the screwdriver and screws approaching?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?