Teacher: “Johnny, why are you down today?”
Johnny: “Because my mom is at the hospital and my dad is at the police station.”
Teacher: “Oh, I’m sorry to hear that, dear. Do you want to go home?”
Johnny: “Yes, please.”
After Johnny has left the classroom, the teacher asks the other classmates,
“Why is Johnny’s father at the police station and the mother at the hospital?”
Classmate: “Because his father is a policeman and his mom’s a nurse.”