1 He was the headmaster of a school for boys.
2 Because when the writer was young,his grandfather gave him presents,and seated him on the knee of his grandfather,and told him stories.
3 He looked at a boy with a different look in his eyes.
4 In the school he is a strict headmaster,but in home he is a kind grandfather.
///楼上第二问的人称代词指代不清
/////when he looked at a boy with a different look in his eyes,that boy went red in the face,and looked down at his shoes.
原文中这句就说明了答案是前半句,His grandfather looked at a boy with a different look in his eyes.意思是他祖父的神色一变,对的