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    Fred likes fish very much. He often buys fish in the shop and takes it home. When his wife sees the fish, she says to herself, “Good! I can ask my friends to have lunch and we can eat this fish.” So when Fred gets home in the evening, the fish is not there and his wife always says, “Oh, your cat eats it.” And she gives Fred some bread for dinner. Fred gets very angry. He takes the cat and his wife to the shop near his house and weighs the cat. Then he turns to his wife and says “My fish weighs one kilo, too. My fish is here, you see. Then where is my cat? ”