Answer:
I run through hills. I veer around mountains. I leap over rivers and crawl through the forests. Step out your door to find me. What am I?
What can be as big as an elephant but weighs nothing?
When it comes to me you go on red and stop on green.
My head and tail both equal are my middle slender as a bee. Whether I stand on head or heel Is quite the same to you or me. But if my head should be cut off the matter's true though passing strange directly I to nothing change.
What gets whiter the dirtier it gets?
I flow from the Homerβs mouth when he sees doughnuts.