Read the excerpt from "Fulton Fish Market." He was beginning to lose hope, when on the eighth day, while Mr. Zanetti was in a loud argument with another merchant, a customer mistook Alfred for an assistant. "Didn't you hear me, boy!? One of those haddock!" the customer shouted.

Alfred scrambled up from the curb. After watching Mr. Zanetti for so many days in a row, Alfred knew exactly what to do. He weighed the fish, wrote the weight and price per ounce on a paper bag, and handed it to the customer.

What theme does this excerpt best illustrate?