Good Riddles

Question: What is in the middle of a human?

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

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

Question: What are the tree mistake in this sentence?

Question: Remembered are the days when I was used, bloodied and beaten... I was abused. Death surrounded me, and it mattered not, as no matter the pain I inflicted, I'd never rot. What am I?