When the classroom was quiet, suddenly a classmate shouted, "What's that smell?" Finally, the teacher was looking for the source of the smell and invite our friends out to clean up. This one event is not everyone's feeling, but there must be one among our friends who have never been like this. Either because the same disgusted school toilets, already can not stand it anymore, or because the responsibility has been out a little continued in continue the rest, still a mystery
