Answer:
Sometimes black, sometimes white, I have veins but no blood
What is it which builds things up? Lays mountains low? Dries up lakes, and makes things grow? Cares not a whim about your passing? And is like few other things, because it is everlasting?
What is a five-letter word that has brain in it?
You must keep this thing. Its loss will affect your brothers. For once yours is lost, it will soon be lost by others.
Two bodies have I, though both joined in one. The more still I stand, the quicker I run.
In your fire you hear me scream! Creaking and whining yet I am dead before you lay me in your hearth.