Answer:
I tremble at each breath of air, and yet can heaviest burdens bear.
An iron horse with a flaxen tail. The faster the horse runs, the shorter his tail becomes.
Talks like this, a green wise man does. Guess my clue, you will.
You eat something you neither plant nor plow. It is the son of water, but if water touches it, it dies.
Runs smoother than any rhyme, loves to fall but cannot climb!
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?