We first established our relationship with Zhang Fengyu on an April day. We made an appointment to go to the largest supermarket in the city. We didn't buy anything, but we came back carrying a huge bucket of vanilla ice cream. The two of us were sitting on the ground facing each other, with the bucket of ice cream in the middle. Each was holding a large spoonful, digging in and putting it into his mouth. Eventually, his face was frozen, and he was still eating "huhuhahaha". He suddenly raised his head and asked: "Is your mouth iced?" While hugging, I found that the unknown tree outside the window was covered with new leaves. When did spring come?