[解析]
(1)C.主旨大意题。根据The school says they feel the ban is necessary to keep order in class.They even gave out an open letter to remind parents not to let their children bring mobile decision.可知本文主要讲述了上海一所中学禁止使用手机的事。故选:C.
(2)B.推理判断题。根据I couldn't help checking if there were messages of missed phone calls.I even played games on the phone sometimes.和Those students who live far from school are allowed to bring mobile phones to get in touch with their parents.可知本文中没有提到学生用手机考试作弊。故选:B.
(3)D.推理判断题。根据I couldn't concentrate during classes if the cellphone was with me.可知,学生认为在学校用手机是不好的。故选:D.
(4)A.词义猜测题。根据The school is also flexible in implementing the ban.可知此处的意思应该是"学校在执行禁令方面也很灵活。" implementing 执行,carrying out 执行。故选:A.
(5)B.推理判断题。根据Those students who live far from school are allowed to bring mobile phones to get in touch with their parents.可知,有些学生仍然可以带手机上学。故选:B.