Read the joke.
Tommy is a pupil. He is always absent-minded（心不在焉的）in class. His father and mother always tell him to listen to the teacher carefully in class.
One day Tommy was having an English class. He was looking out of the window and smiling. His English teacher asked the class, "Please say two pronouns." Tommy looked at his teacher in surprise and stood up, "Who? Me?"
The teacher nodded, "Good! Sit down, please."