Final answer:
In the book 'Wonder' by R.J. Palacio, August 'Auggie' Pullman's best friend before attending school and before Christopher moved away was Christopher.
Step-by-step explanation:
In the novel Wonder, August "Auggie" Pullman's best friend before he started going to school was Christopher. August did not attend school initially due to his many surgeries and the fear of how others would react to his facial differences. Christopher was his friend before he moved away when both families lived in North River Heights. As August enters a new school, he forms new friendships, notably with Jack Will and Summer, but the story also touches upon the challenges he faces due to the initial lack of acceptance from some of his peers.