Mr. Dawson is an old man and he never smiles or talks to anyone, so when kids see him, they often feel afraid. 

One day, 12-year-old Janet and her friend Amy have to walk past Mr. Dawson's house. When Janet sees him outside, she tells Amy that they can cross the street and walk on the other side. But Amy says they don't need to do that. When Mr. Dawson sees Amy, he smiles and says, "Hello, Amy! I see you have a new friend with you today. " Amy smiles back. Mr Dawson is friendly and gives them each a fresh apple. Janet opens her eyes,and also her mouth.Later, Janet asks Amy, "Everyone says he is not a kind old man in town. Why is he so kind to us?" Amy says, "When I first walk past his house, I also want to cross the street and walk on the other side. But I know I can't do that, so I pretend (假装) there is an invisible (看不见的) smile on his face and start talking to him with a smile. At first I only say hello but then I talk to him more every time I see him. "

"An invisible smile?" Janet asks. "Yes, " answers Amy. "My grandma tells me that smiles can pass from one to another. So if I smile at someone, they will smile back. "