Answer:
I am so simple that I can only point. Yet I guide men all over the world.
A nut cracker up in a tree.
The eight of us move forth and back. To protect our king from the foes attack.
What can be filled with empty hands?
What I am filled, I can point the way. When I am empty. Nothing moves me. I have two skins. One without and one within.
Lynn likes grapes but not potatoes. She likes squash but not lettuce, and she likes peas but not onions. Following the same rule, will she like pumpkins or apples?