Answer:
I tremble at each breath of air, and yet can heaviest burdens bear. What am I?
If you have me you want to share me. If you share me you don't have me. What am I?
What kind of tree can you carry in your hand?
You seek me out when your hunger's ripe. I sit on four legs and smoke a pipe.
Die without me, never thank me. Walk right through me, never feel me. Always watching, never speaking. Always lurking, never seen. What am I?
When is it bad luck to see a black cat?