How does Mr. Donleavy nearly destroy Marguerite's much anticipated graduation? What inequities does he reveal?

Mr. Edward Donleavy, a kind of school superintendent, is the graduation speaker. He tells of the improvements and opportunities coming to the white school in town, Central High; then, he mentions that two recent graduates of the Lafayette County Training School are now successful athletes. Maya feels completely insulted; although white boys and girls get plenty of opportunities, Mr. Donleavy seems to say that the best black boys can do is to become athletes, and doesn't even mention the girls.