Answer:
Two in a whole and four in a pair. Six in a trio you see. Eight's a quartet but what you must get is the name that fits just one of me.
When I am caught I am thrown away. When I escape you itch all day.
I am round. I have only one line. Circle is not my name indeed. What am I?
You throw away my outside you cook my inside. Then you eat my outside and you throw away my inside.
Die without me, never thank me. Walk right through me, never feel me. What am I?
What never gets any wetter no matter how hard it rains?