the teacher walked in to the classroom . He said, good evening , everybody . The students said, good evening , teacher . He walked over to his desk. He put his briefcase on his desk . He opened his briefcase . He took his notebook out of his brief case . He look his books out of his briefcase. Suddenly , He felt dizzy . The room was spinning . He sat down. What was wrong with ? He put his hands on the desk . The desk was spinning. He closed his eyes . He opened his eyes. He didn't know what to do. What was wrong ? He was sitting in his chair . But he felt like he was floating in air . How could he be floating in air? He sat in his chair for another minute. His students were talking to one another.they did not know how he felt . But he didn't tell them how he felt. He didn't say anything.