There is no doubt that cell phone has been part of our life. We use it to keep in touch with our friends and families. Its functions have been developed a lot as time goes by. Almost every middle school student has a cell phone, but some overuse it. In the classroom, when teachers are presenting knowledge, but the students are lowing down their heads playing cell phone. So the teachers advocate students not to bring their cell phones into classroom. But who can actually make it? It is better to let students realize the overuse of cellphone makes them study with lower efficiency.