After an absence of thirty years, I decided to visit my old school again. I had expected to find changes, but not a completely different building. As I walked up the school drive, I wondered for a moment if I had come to the right address. The dirty red brick houses had been swept away. In its place stood a bright, modern block. A huge expanse of glass extended   across the face of the building, and in front, there was a well-kept lawn   where previously there had been "an untidy gravel   yard". I was pleased to find that it was bread time and that the children were all in the playground. This would enable me to meet some members of staff . On entering the building, I was surprised to hear loud laughter coming from what appeared to be the masters' common room. I could not help remembering the teachers in my time, all dressed in black gowns   and high collars  . And above all, I recalled Mr Garston whom we had nicknamed "Mr Ghastly", the headmaster who had iron discipline  on staff and pupils alike. I knocked at the common room door and was welcomed by a smiling young man who introduced himself to me as the headmaster. He was dressed casually in a sports jacket, and his cheerful manner, quickly dispelled   the image of Mr Ghastly. After I had explained who I was, the headmaster presented me to the teachers all of whom were a little younger than himself, and said he would take me round the school. Here the biggest surprise of all was _  me. Gone were the heavy desks of old with their deeply carved names; gone too, were the dark classrooms with their ink stained, dark brown walls, and their raised platforms for the teachers. The rooms now were painted in bright colors, and the children, far from sitting straight in their places, seemed almost free to do as they liked. I looked with envy  as I remembered how, as a child, I had looked at the blackboard hardly daring to whisper to my neighbor. Mr Ghastly must be   _  .
the writer's teacher a serious old man the strict headmaster a naughty boy