Answer:
I go up and down at the same time. Up towards to sky and down towards the ground
What has a head and a tail but no body?
I have keys but no locks. I have space but no room. You can enter but can't go outside. What am I?
I am a type of weapon for SCI-FI characters
I'm light as a feather yet the strongest person can't hold me for more than a few minutes. What am I?
I flow from the Homer’s mouth when he sees doughnuts.