Fred likes fish very much. One day, he buys a fish. His son sees the fish and says to himself（自言自语）, "Very good!I can ask my friends to have it for lunch. "
The next day, Fred comes home in the evening. The fish isn't there. His son says. "Oh, Dad. Your cat eats the fish. "Fred gets angry. He takes the cat and his son to the shop and weights（称重）the cat Then he says, "Lite boy. My fish weights one kilo, and the cat weights one kilo, too. My fish is here, and then where is my cat?"
