What we do: Let a classmate call the teacher, while others hide. Seeing that no one was ready to leave, the teacher jumped out and shouted "teacher" together, and then rushed up to hug the teacher together. Others took photos and recorded them, and handed them to the teacher together with a book full of blessings. If it is a boarding school, it is better to act at night. Remember to turn off the lights when the teacher is surprised. You can create an atmosphere by candlelight.