It's undeniable that smart phones are playing a vital role in every sudent's life. Therefore, I think that smart phones shouldn't be banned among them. First, smart phones are useful devices that help students a lot in their studying. They can search for math solution, history stories,... to understand lessons better and get higher scores. Second, formers teacher could use phones to contact with his/her student conveniently, for example to inform an notice which is emergent. Morever, there are so many applications which support students' studying, teachers no longer have to spend time explaining complicated problems to their students. Thankfully with the help of smart phones, students can understand on their own. In conclusion, I strongly support the idea that smart phones shouldn't be banned among student as aforementioned reasons