Young generation nowadays have useduse cell phones like an indispensable commodity that goes along with them in any pace of life , even at schools or in classrooms.
... keep this in present tense. Also the part I highlighted sounds a bit confusing as to what you mean :(
students using cell phones in secondary and high school is unacceptable for some following reasons.
The initial important reason of not allowing students using cell phones at school is to avoid thepossible cheating situation inat the exams .
Obviously , cell phone useusing cell phone during class impact detrimentally on student's process of attention and level of contributation , many teenagers suffer from pemanent partial attention disorder, which is a habit of paying only partial attention to their schoolwork, while devoting half of their attention, typically , to social networking sites or instant massaging.
... this line is too long and the reader has to make a great effort to remember its details. With less work for the reader, he would find your essay more interesting. :D ... Try and avoid very lengthy sentences.
Also, when you make new posts, post these essays under "Writing Feedback" forum.
Overall a good essay as always ;)