Answer:
What jumps when it walks, but sits when it stands?
I have a straight back and sharp teeth to cut objects.
There's not a kingdom on the earth I haven't traveled over and over and though I know not whence my birth yet when I come you know my roar. I through the town do take my flight and through the fields and meadows green and whether it be day or night I neither am nor can be seen.
I have lakes but no water forests but no trees and cities but no buildings. What am I?
I come with a train and go with a train and the train doesn't need me but can't go without me.
What did the piece of wood say when he saw the screwdriver and screws approaching?