The passage tells a short part of the story of Helen Keller and her teacher miss Sullivan. Their story has inspired educators and people alike worldwide and it has served as an inspiration to help people around the globe.
Helen Adams Keller was born on June 27, 1880 in Tuscumbia, Alabama. In 1882, she was afflicted by an illness that left her blind and deaf. In 1887 she met her life-time teacher, companion and friend Anne Sullivan. Miss Sullivan helped her make tremendous progress with her ability to communicate, and Keller went on to college, graduating in 1904. In 1920, Keller helped found the ACLU (American Civil Liberties Union). During her lifetime, she received many honors in recognition of her accomplishments.
The answer to the question of how the sentence given in the short passage functions, we must say that:
It introduces the idea that Sullivan is a masterful teacher who changes Keller's life.
