Essentially, ethos is about believability. Will your audience find you believable? What can you do to ensure that they do? You can establish ethos or credibility in two basic ways. You can use or build your own credibility on a topic, or you can use credible sources, which in return builds your credibility as a writer
Most insurance companies would rather you not do anything about collecting claims until they investigate the situation. This question is tricky because you need to make sure that the phrase you put in the blank says an action rather than just saying don't or did not.
