Only two back bones and a thousand ribs. What am I?

Answer: Railroad track.

More What am I ? with answers

More What am I ?

People always ask for me even though they don’t like to face me. What am I?
People buy me to eat, but never eat me. What am I?
People need me yet they give me away every day. What am I?
People say I put doctors out of business, sometimes I am sour, sometimes I am sweet, I can be eaten and can also be drunk. What am I?
People walk in and out of me. They push and I follow. When they walk out on me, I close up and I stay waiting for the next person to walk into my life when I have a more open mind. What am I?
Physicists have built devices to make me move quickly. My last eight letters can be commonly found in newspapers, magazines, and journals. What am I?
Physicists have built devices to move me very fast. My last seven letters can be commonly found in newspapers, magazines, and journals. What am I?
Poke your fingers in my eyes and I will open wide my jaws. Linen cloth, quills, or paper, my greedy lust devours them all. What am I?
Ripped from my mother's womb, beaten and burned, I become a blood-thirsty slayer. What am I?
Ripped from my mother's womb. Beaten and burned, I become a bloodthirsty killer. What am I?
Round and round, never off the ground. What am I?
Round as a button, deep as a well. If you want me to talk, you must first pull my tail. What am I?