Many years ago I taught English in a very rough school on the outskirts of Angers France. On my first day I walked into a class full of 17 year olds who had resat year 11 twice and really weren't interested in learning English especially from some student! They were all layed along the desks and just stared at me. I decided that confrontation was what they were after so just carried on as if nothing was wrong. Slowly but surely they sat down one by one and by the end of the year we were all best of friends. Show no fear!! Never talk down! I now teach year 1 but the principles are the same.