阅读理解
Mobile phones have become a problem for middle schools.The Education Department of China has announced that schools should ban （禁止） students from carrying mobile phones during school hours.
Mobile phone use among children has become a problem.Several children have got mobile phones from parents and relatives as gifts，and more students will want them.
An expert said mobile phone use was a distraction（分心的事） to students during school hours.Teachers were also saying that sometimes students might use phones to chat or play game in class.Some students could use them to cheat during exams.
The expert said some schools had tried to ban mobile phones.Some parents felt unhappy because they couldn't call up their children.
Many teachers said students should not have mobile phones at school，but if there was a good reason，they could leave their phones at school office.
Many people say that they understand why parents would want their children to have phones，but they think schools should let the students know when they can use theirs mobile phones.
The mobile phone is a double—edged sword（双刃剑）for teenagers.How to solve the problem reasonably？It's well worth considering.