Answer:
The more there is the less you see.
From house to house I go, sometimes narrow, sometimes wide. Whether there's rain or snow, I always stay outside. What am I?
I only exist when you are here. Where you never were I can never be.
I am the place to turn when nature calls.
Who plays when he works and works when he plays?
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?