单选题
Jo was the most popular boy in the school. He was tall and strong, with dark brown hair and green eyes and the sweetest smile. He was good at all sports and he was top of his class. There was keen competition among the girls to attract his attention. Yet, Jo was nice to all of them, even the plain, shy ones but he didn't have a steady girlfriend. Ella was the only one who didn't seem to have any romantic interest in him; she treated him friendly and the others didn't consider her as rival. But she knew him very well. Jo and Ella were the best friends. They talked about their problems, exchanged ideas, gave advice to each other and played jokes on each other occasionally. One day, Jo didn't go to school. He stayed away for a week, then the news came: his mother had died. When he went back to school, he looked tired and sad, like someone who walks without knowing where he's going. No one knew what to say to him. The easy smile and superficial chat couldn't reach him any more. When he met Ella, they didn't say much. There was no need to. She simply shook hands with him, then hugged him briefly and asked him to go and see her in the afternoon. It all started right then.