Summary of story: recommended by a friend, a little boy came to my library to help sort out books. Then the little boy moved away, and I missed him very much. But the next day, I saw the little boy come to help. I think he is very talented. He is Bill Gates.

We can see from the little boy's carefulness, patience and perseverance that he is a competent librarian. After moving, he still cares about his "work" in the library.