As a boy, Mark Twain caused much trouble for his parents. He used to play practical jokes on all his friends and neighbors. The nature of his jokes often led to violence  . He hated to go to school and he constantly ran away from home. He always went in the direction of the nearby Mississippi. He liked to sit on the bank of the river for hours at a time and just gaze at the mysterious island and the passing boats. He learned many things about the river during those days. He learned all about its history and unusual people. He later made them part of the history of America in the book Tom Sawyer and Huckleberry Finn. Mark Twain received his genius   from his mother. Obviously he didn't get it from his father. He once stated that he had never seen a smile on his father's face. On the other hand, his mother had the ability to say humorous things. The same ability made Mark Twain an extremely humorous public speaker. According to the passage, Mark Twain was a   _   boy.
shy brave naughty poor