1. What’s at Earth’s Core?
A solid ball of iron as big as the moon and, there is also a churing ocean of liquid of some sort between the iron ball and the mantle, but scientist are not sure of what it is.

2. Why do we sleep?
Well one reason for why we sleep is that we can die if we get no sleep. We sleep to rest out brain and replenish everything from that day. All mammals need to sleep for there own good you, die faster if you get no sleep then getting no food.

3. Why do we die when we do?
Our system just starts failing and dying and our body starts breaking down. Ours cells start shrinking and as we get older we develop problems. In animals the bigger you are the longer you live but, for humans the bigger and taller you are the shorter life span you have.

4.Why can’t we regrow body parts?
We can't regrow body parts because we don't have the type of tissue that certain animals have inorder to do that. The animals body almost retraces its steps and go back in time and they make a new organ or limb. They still can't fully figure out why we can't grow back body parts even though we have almost the same systems but, some parts in our bodies can recover small parts.