Answer:
Weight in my belly, trees on my back, nails in my ribs, feet I do lack. What am I?
I have a head tail but no arms and legs.
I build up castles. I tear down mountains. I make some men blind, but I help others to see. What am I?
I am a king who’s good at measuring stuff. What am I?
I don't live within a house, nor do I live without. Most will use me when they come in, and again when they go out. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.