Answer:
I run up and down the stairs without moving. What am I?
I have two bodies joined together as one. When standing still, I run and run. What am I?
I wiggle and cannot see; sometimes underground and sometimes on a tree. I really don't want to be on a hook and I become a person when combined with “book”.
When it comes to me, you go on red and stop on green. What am I?
I am a shimmering field that reaches far. Yet I have no tracks and am crossed without paths.
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.