Everyone Can be Hero

Everyone can be a hero. I think a hero is a person who sincerely sacrifices himself for many people or the environment. From the small example, street sweeper also can call as a hero. Why? because without them the road will not clean all the time. Many people just throw their rubbish everywhere. They do not realize the effect to their environment. Then who will clean up the rubbish if it is not the street sweeper? It seems so easy to become a street sweeper.