Being a product of high-technology,mobile phones are being more and more widely used. It‘s small in size, light in weight and easy to carry, offering fast and convenient service for ‘s of multi-function. The users use it for calling, sending short messages and internet-surfing. In recent years, mobile phones have become popular among middle school students. 　　Quite a few use them at school to keep in touch with their families and friends instead of writing letters, which, of course brings convenience to them. But I don‘t think it‘s good to do so. In spite of the advantage mentioned above, student users often waste a lot of time chatting over the phone in their spare time, some even use them to cheat in exams. In addition, mobile phone bill is also a heavy burden on students‘ families