Answer:
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I’ve told you all I cannot tell you more.
I fill a room but take no space. What am I?
I have skin, more eyes than one. I can be very nice when I am done. What am I?
What is the difference between a poorly dressed man on a bike, and a well-dressed man on a unicycle?
I fly forever Rest never.
What sphinxes employ and players enjoy.