"What are you doing?"

"My homework." The boy put down his pen. "It's on states of matter."

"Oh?" his mother asked. "So - like the differences between solids, liquids and gases?"

"Yeah. I've got to come up with ten examples of each. It's not that easy."

"Ha!" The boy's mother shook her head and smiled. "Alright. What about a table?"

"Easy. Solid."

"Water."

"Liquid."

"So what's the problem?"

"How about a cat?" the boy asked.

"Easy. They're solid."

"No they're not." The boy reached down and picked up his cat. It melted through his fingers and hurried away with feline dignity.