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Jim is a boy. He's twelve years old. He has a twin(孪生的) brother，Ben. They look the same but they have different hobbies. Jim likes reading books and lis-tening to music, but Ben likes playing sports.

Jim is tall. He is 1.58 meters. Ben is 0.02 meters taller than Jim. Jim is sad. because he isn't good at sports. But Ben can run faster and jump higher than him. Ben is also not happy. He's worried about his maths.

So they begin to help each other. Ben usually plays basketball with Jim after school. And Jim often helps Ben with his maths. Now Jim's stronger than before. Ben's maths is as good as Jim's. Both of them become better and better.