They are called compound sentences.When 2 sentences are connected.
Yes, heroes have responsibilities in that they are relied on to save the day. Without them there, people would be susceptible to any form of crime and if the hero fails, they end up hurting their reputation and the citizens they are trying to save. Not to mention, with a hero around, cops and firefighters tend to slack off on the job more, mostly because they know the hero will get the job done. So, if the hero wasn't there, the "trained" emergency professionals will be in for a loop. (Not the best writing, suggest you edit it to whatever way you like, but the main aspects of the weight of responsibility a hero has have been brainstormed for you.)
A word used to describe an action
Well usually when I'm doing a report I would develop well thought out paper and before that analyse the pages and facts.