Depending on what Internal Organ you are referring to your Rib cage covers over your Heart, lungs, and a few other organs.
A hard cover or, hardback book has a hard, thick and inflexible cover. It is more expensive and is the first format in which a book comes out. When a book first comes out, it is available only as a...
Viscera. I'm pretty sure that's the word you're looking for.
i tink is 30% of the weight.
Uhmmm I think so?