⓵ 주제문 -> Nowadays some may hold the opinion that advertising can tell you a lot about a country.
⓶ 뒷받침 문장 1 -> Advertising varies from country to country, depending on the country's particular conventions.
⓷ 뒷받침 문장 2 -> A further more subtle point we must consider is that we can understand a country by its products.
⓸ 마무리 문장 -> In short, advertising can really tell you a lot about a country's culture and customs.