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. 
毫无疑问，手机已成为我们生活中的一部分。我们用它来与我们的朋友、家人保持联系。随着时间的流逝，越来越多的手机功能被开发出来。几乎每个中学生都有一台手机，但是一些人却是过度使用。在课堂上，当老师们在讲授知识的时候，学生们却在低头玩手机。所以老师提倡学生不带手机进教室。但是又有谁能做到呢？最好是让学生认识到过度使用手机会使降低他们的学习效率。