Grandpa buys ice cream for his granddaughter, and the granddaughter buys ice cream for his grandfather.

In summer, my sister and I watch TV at home. I felt very hot, so I asked my mother, "Can I buy ice cream?" Mom said, "Yes." I walked to the supermarket happily.

Then, I went to the refrigerator and saw all kinds of ice cream in it. I look for my favorite ice cream in the refrigerator. When I picked up my favorite ice cream, I couldn't help rushing home with it. When I got home, the ice cream melted. I took the ice cream and said to my mother, "Sorry, Mom, the ice cream melted." Mom said, "Never mind." I asked my mother again, "Why does it melt?" Mother said: "Because the temperature of ice cream is very low, it will melt when it meets hot air." After listening, I nodded and put the ice cream in the refrigerator. After a while, the ice cream changed back to its original appearance.

Although nothing special, I am also very happy, because I know a scientific knowledge.