Once there was a rich man who lived with his wife and child.He loved the child so much that he sent him to Oxford university for two or three years.At the end of the first year at the university, this young student came home.He wanted a change.And he also wanted to tell his parents about Oxford. It happened one night that the father, the mother and the young student were sitting at supper.They had in front of them only two chickens.Just as they were about to begin eating, the father said, "My boy, I have spent a lot of money on you to send you to Oxford.Now I want to know what you have learned."The son smiled and said, "Father, I have studied a science which can prove  that these two chickens on the plate are really three chickens.""Well," said the father, "This is something I would like very much to know.""There are two chickens on the plate, "said the student.He took one of the chickens in his hand and said, "Here is one more ; and one and two makes three.So here are three chickens."Then the father took one of the chickens to himself, gave the other to his wife, and said, "I will have one of the chickens myself, your mother shall have another, and you can have the third for your supper and nothing else."The father kept his word and so the student went without his supper. (5) The student said that   _  .
hecouldmakethreechickens hecouldchangethetwochickensontheplateintothree hecouldprovethetwochickensontheplatewerereallythree hewasgoodatmaths