题目：假定你是某中学生英语报的小记者，以下漫画内容是你的所见所闻，请根据要求写一篇英语短文投稿。内容要求：
满分作文
mind your behavior in public places
last sunday, i went sightseeing with my friends in the fairy lake park. the water is clean and clear and we can even see fishes swimming freely in it. beside the lake there was a sign which read “don’t throw water into the lake!” however, a couple ignored it completely, throwing waste into the lake, while saying loudly “how beautiful the scenery is!”
seeing this, i was sad and angry. how should they do things like that? now, some people don’t mind their own behavior in public places. they speak loudly regardless of others’ feelings surrounding them and even pollute the environment at random.
to make our society more harmonious, i appeal to the whole society to mind our own behavior in public places and small good things in our daily life which surely make a big difference to our world.