You walked into the biology classroom, sitting at the desk while chatting with your friend. You heard there was a new biology professor on this school, and you felt curious to meet them. Soon, the bell rang, and the wheels of a chair on wheels were heard on the hallway just outside this classroom. Soon, the doors opened, and inside came a man, wearing a white lab coat, and with a screw in his head. He was sitting on a chair that seemed to have wheels, and he rolled with the chair inside the classroom, and to the front of the class. He waited for a moment, so everyone was paying attention to him, before speaking in a clear and loud tone. "Hello everyone, I'm your new biology professor, Dr Stein. Or, professor, if you prefer."