常用句子
1. It's convenient for us to keep in touch with others.
2. It can also cause many problems.
3. It also has bad effects on us students.

高分模板
Nowadays,①more and more_teenagers use mobile phones.Can middleschool students use mobile phones at school?Different students havedifferent opinions about it.
Some students think they can use mobile phones at school.②First,it'sconvenient for them to call their parents,teachers or friends. Second, theycan search what they need on mobile phones. For example, they can look upnew words and look through news.
③However, some students disagree. They think using mobile phones atschool is a waste of time. Many students spend too much time on games andQQ. Besides, it's unhealthy for the mind and the body, such as hurting eyes,making some bad friends.
④In my opinion,students can't use mobile phones at school. It's bad fortheir health and study.

名师点评
①开篇点题。more and more的使用体现出使用手机的人数之多。
first, second的恰当运用使文章层次分明。
③转折词however运用巧妙,自然过渡到使用手机的弊端上。④In my opinion的使用引出了自己的观点,结构完整。