Answer:
You throw me out when you use me and take me in when you are done.
I help you carry your books.
I jump when I walk and sit when I stand. What am I?
People need me, yet they give me away every day. What am I?
I can sizzle like bacon. I am made from an egg. I have plenty of backbone but lack a good leg. I peel layers like onions but still remain whole. I can be long like a flagpole yet fit in a hole.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?