As far back as 700 B. C, man has talked about children being cared for by wolves. Romulus and Remus, the legendary twin founders of Rome, were said to have been cared for by wolves. It is believed that when a she-wolf loses her litter, she tries to get human child to take its place. This seemingly foolish and unreasonable idea did not become believable until the late nineteenth century when a French doctor actually found a ten-year-old boy having nothing on wandering in the woods. He didn't walk upright, could not speak understandably, nor could he relate to people. He only growled and stared at them. Finally the doctor won the boy's confidence and began to work with him. After many long years of devoted and patient teaching, the doctor was able to get the boy to clothe and feed himself, recognize and say a number of words, as well as write letters and form words. The doctor was able to work with the boy because   _  .
the boy had never lost his mind the boy trusted him the boy liked to dress up the boy worked very hard