Answer:
A little pool with two layers of wall around it. One white and soft and the other dark and hard, amidst a light brown grassy lawn with an outline of a green grass. What am I?
You may enter, but you may not come in. I have space, but no room, I have keys, but open no lock. What am I?
Some will use me, others not. Some have remembered, others forgot. For profit or gain, I'm used expertly. I can't be picked off the ground or tossed into the sea. What am I?
What goes up and down but does not move?
What has to be broken before you can use it?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.