While the move by the wireless Internet the aim by the time will pass so you will waste time on other activities such as a waste of time to review the lessons make bad grades.
While the Internet indefinitely without aim, by the time it is over, so you'll waste time doing other activities. Such a waste of time to review the lessons. It was a bad grade
While the Internet around without a purpose by the time will pass passive you will waste a lot of time to do other activities. Such as the time to review the lesson makes a bad grade.