Askateachertonamethemostannoyinginventionofrecentyearsandtheywilloftenmentionthemobilephone．Disturbedbytheproblemstheycreate，manyheadteachershaveorderedthatpupilsshouldkeeptheirphonesswitchedoffatschool．Oth

　　Ask a teacher to name the most annoying invention of recent years and they will often mention the mobile phone．Disturbed by the problems they create，many head teachers have ordered that pupils should keep their phones switched off at school．Others have told pupils to leave them at home．

　　However，education researchers at The University of Nottingham believe it is time that phone bans were reassessed，because mobile phones can be a powerful learning aid，they say．Dr Elizabeth Hartnell-Young and her colleagues have reached this conclusion after studying the consequences of allowing pupils in five secondary schools to use either their own mobile phones or the new generation of‘smartphones'in lessons．

　　During the nine-month experiment，14-to-16-year-old pupils used the phones for a wide range of educational purposes，including creating short movies，setting homework reminders，recording a teacher reading a poem，and timing experiments with the phones'stopwatches．The smartphones，which could be connected to the Internet，also allowed pupils to access revision websites，log into the school email system，or transfer （转存） electronic files between school and home．

　　The research involved 331pupils in schools in Cambridgeshire，West Berkshire and Nottingham．"At the start of the study，even pupils were often surprised at the thought that mobile phones could be used for learning，"Dr Hartnell-Young said．"After their hands-on experience，almost all pupils said they had enjoyed the project and felt more inspired．"

　　Some teachers found that pupils who lacked confidence gained most from the project．However，they recognized that greater use of mobile phones in schools could cause problems．

　　12．We can infer from the first paragraph that___．

　　A．teachers are strongly against students owning mobile phones

　　B．mobile phones should be developed to meet students'needs

　　C．students are free to use their mobile phones at sc