When class begins, most teachers will be annoyed by the problem of missing few students. When the class begins and the students will come to classroom one by one. The teachers will be interrupted and ask them why they are late for class. Then all kinds of funny reasons come out. Some students say that the clock is broken and they miss the right time, some say that there is something wrong with their stomaches, even some say that they have a robbery on the way to school. After hearing these reasons, the teachers can’t help laughing out, they see through the students’ little tricks but they can’t criticize them directly. Then the teacher will give them another chance, but next time they need to show the proof. How to deal with such problem is a hard job for teachers, a good teacher can always find a effective way to reduce it.