Good Riddles

Question: I can't go left, I can't go right. I am forever stuck in a building over three stories high. What am I?

Question: What has teeth but can't bite?

Question: How do you make 9 by just 3 toothpicks?

Question: What's a plate when it has three spoons in it?

Question: I start at the beginning and I finish at the end I fly through the middle and I return again.