Answer:
What can fill up a room that takes up no space
What do you call a duck that is addicted to drugs?
I walk on 4 legs in the morning, 2 legs at noon, and 3 legs at night. What am I?
What has four legs, but can't walk?
What do elves learn in school?
I am used for light yet I am solid. Without me you would feel enclosed. I hate being touched especially with a lot of force. I like to be in buildings.