At present, mobile phones are become more and more popular. According to the report, about 57% students have mobile phones. Some students use them to search new words and ask for new information and knowledge. Some use phones to listen to music and take some interesting pictures. And they can call teachers, their parents or policemen when they are in need. But every coin has two sides. There are also some disadvantages brought by the phones. Some students use them to play games, which is bad for their sleeping and study. Besides, some students chat with strangers and learn bad habits. Some read unhealthy novels. They use phones to send message when it is time to sleep. So, I think everyone should use phones correctly. If you use it properly, you can benefit from it; otherwise, it will waste your time and ruin your life.

题目分析：这是篇命题作文，题中给出了写作的要点信息，在作文中要尽力体现出这些要点。注意文章结构的严谨和逻辑性。文中可使用一些承接性的句子和短语来加强文章的流畅性。

【亮点说明】这篇文章结构严谨，要点齐全，表达准确流利；文中使用了很多有用的表达方式，如：According to根据；But every coin has two sides.但是每个硬币都有两面；listen to music听音乐；Some students use them to play games, which is bad for their sleeping and study一些学生用来玩游戏，这对他们的睡眠和学习有不好的影响；which引导一个非限制性定语从句。