阅读下面短文，根据所给情节进行续写，使之构成一个完整的语篇．

注意：1．所续写短文的词数应为40﹣50词；

         2．必须至少使用2个短文中划线的关键词语；

         3．续写部分至少一段，第一段开头语已经为你写好；

         4．续写完成后，请用下划线标出你所选用的关键词语．

   Today，more and more teenagershave their own smart phones．Can middle school students use smart phones at school？Different students have different opinions．

   Some students think they can usethem at school．It's convenient for them to call their parents，teachers or friends．And they cansearch what they need on smart phones．

    Paragraph1：

   However，some students disagree． _____________．