Answer:
You are my brother, but I am not your brother. Who am I?
You write on me and secrets I can keep in places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?
What goes through cities and fields but never moves?
I have keys but no locks. I have space but no room. You can enter but can't go outside. What am I?
I'm where yesterday follows today and tomorrow is in the middle. 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.