Answer:
I tremble at each breath of air, and yet can heaviest burdens bear.
In buckles or lace, they help set the pace. The farther you go, the thinner they grow.
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around.
Goes over all the hills and hollows. Bites hard, but never swallows.
In the forest, this blends in just right, but every December it is covered with lights. What is it?
What did the piece of wood say when he saw the screwdriver and screws approaching?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?