关于别把手机带进教室

he asked the boy, pointing at the sign above the blackboard. The boy looked as if he hadn't realized what had happened to him. Ee must have forgotten to turn the phone off before class. However, the boy wasn't able to escape from the school punishment.
I think students shouldn't use cellphones in school. The ringing of the phone in class not only interrupts teachers, but also spoils the class.