My 8-year-old daughter is making an experiment. She has been making her own colorful smile cards and often takes them with her everywhere. Last Sunday, I took my kid to go shopping with me. She was hoping to see John, who is an elderly man and gives out samples. We see him from time to time and he is so happy and friendly. John wasn't at the store on Sunday, so my daughter decided that it would be a good idea to _ her smile cards to the store's other employees. So she did. In the produce department, she gave a card to a young man and she hoped it would make him smile. And he smiled at her and thanked her. Then she came across an older gentleman who looked rather impatient. And she snuck a card into his cart on top of his groceries, remarking to me later that he looked at her suspiciously as if she was dumping trash in his cart. But I thought he would be happy later. When we got back from our shopping trip, she had run out of cards. She was walking by a woman with two babies in her cart. My daughter smiled at her and the young mother smiled back. My daughter came to me and said excitedly, "Mom, I just realized something. You don't need cards to make someone smile. All you need to do is make eye contact and smile into their eyes and they will smile back." What a beautiful lesson my daughter reminded me of. You are never too young or too old to experiment with kindness and smiles. From the text, we can learn that   _  .
John got a smile card from the writer's daughter the older gentleman would smile later after he got the smile card we could make others smile only by giving them what they wanted the mother with two babies smiled because she got a smile card