Answer:
What belongs to you but others use it more than you do?
I hold two people together but touch only one. What am I?
I fly yet I have no wings. I cry yet I have no eyes. Darkness follows me. Lower light I never see.
You may enter, but you may not come in. I have space, but no room, I have keys, but open no lock. What am I?
I build up castles. I tear down mountains. I make some men blind, I help others to see. What am I?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.