My grandfather was a teacher. He was the headmaster of a school for boys between the ages of thirteen and eighteen. I know that he was a kind and gentle man at heart, because when I was young (and he was old), he gave me presents and seated me on his knees, and told me stories. But I believe the boys at his school were afraid of him. At school, when he walked into a classroom full of noisy boys, those boys went red in the faces, and looked down at their shoes. If a boy brought him poor, careless work, which was not the best that boys could do, my grandfather picked up the boy's work and threw it across the classroom, shouting, "Do it all again, and bring it back early in the morning!" If the boy was late, or if he forgot to bring the work, he had to do it again. My grandfather never forgot. He was a very different man at school, from the man I saw day by day in his own home. He was a different man at home because   _  .
he didn't get angry at home he was not as gentle as at home he didn't throw work at school like he did at home he didn't get angry at school like he did at home