What's a good friend like? One may have different answers to this question at different ages. When he is very young, he may think a good friend must be together with him all day. And they can share everything together. If his friend doesn't give him food to eat once, he doesn't think they are good friends any more. But they will play together happily again very soon. When he grows older and studies in a middle school, his idea about a good friend changes. He thinks a good friend should be helpful and honest. A good friend should always help him with his lessons. A good friend should come to him when he is sad. And he is always ready to tell everything to his friend. If his friend tells others about his secrets, he may hate the friend. When he grows up, he may not think it's necessary for a good friend to be always honest. Everyone has his secrets. If the truth  may hurt the friend, it's better to keep it secret from him than tell him about it. And he may think a good friend can give him some good advice when he has problems. He comes to understand that he shouldn't just ask friends for help and that he should also learn to do something for his friends. We should keep it secrets from our friend when   _  .
he is very young he grows up he is unhappy the truth may hurt him