By the way, I want to tell you what I learned many years ago in a politology class. The professor said that there are many Americans from Central America and South America, who are against that only the USA are called "America". I don't know how many are they and is it still an issue nowadays but it makes good sense. Yes, there are many people, for example in Europe, who think that "America" and "USA" ("US", "United States") are interchangeable but, in fact, we have to know that "America" is an umbrella term. It means the continent America ("美洲" in Chinese), but in fact there are 2 Americas (North America and South America).