Answer:
I am the kind of a tree that is carried in your hand. What am I?
As a state in America I am round on both sides and high in the middle.
I am lighter than air, but a hundred people cannot lift me. Careful, I am fragile. What am I?
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. What am I?
Who is the most foreign visitor you could imagine?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?