The math teacher in our class is a young male teacher. His name is Jiangshan. He is tall and fat, so we call him "Big Man". He didn't get angry when he found out, and he said his nickname was cute. Teacher Jiangshan is easy to get along with and interesting. We can play a joke on him. But he is very serious and patient about our study. We can't be careless in our study. If we have any questions, please feel free to ask him. He is a very good teacher.