Answer:
What goes up but never comes down?
Some live in me, some live on. And some shave me to stride upon. I rarely leave my native land. Until my death I always stand. High and low I may be found. Both above and below ground.
I build up castles. I tear down mountains. I make some men blind. I help others to see.
The man who made it didn't need it. The man who bought it didn't use it. The man who used it didn't want it.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.
When is it bad luck to see a black cat?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?