My father is 75 years old. One day, a crow flew.He asked: "Is this what?"Son: "It's a crow."After a while, my father asked again. The son said: "It’s a crow, what's the matter with you!" One day later, the son opened the diary of his father 40 years ago."Today my son is three years old. He pointed to the crow in the park and asked me: What is this? I told him that it was a crow. He asked again, I answered again. He asked 11 times and I answered 11 times."