The fact "an island is used for walking on" is illustrated with the story:1. I tried to swim in an island but there wasn't any water on the island.2. I thought about flying over the island but I lacked a plane.3. I tried to have a big party on the island but nobody lived there so I was the only person who came.4. I tried to fish on the beach but it required a fishing pole I didn't have with me,5. I decided to walk on the island since that didn't require anything but me and a small bit of land.