Hi Nelson, You are referring to a specific niece (Maria Shiver). Therefore, the article to be used in the blank is "the". Hope this helps. Cheers, Lance

That's because it's not "us", it's US or U.S. as in "United States".

(1) The answer is "a." There are tons of penniless 21 year-olds. He was just one of many. (2) This is a bad question. As Mr. Lance said, the answer could be "the" because the sentence refers to a specific niece. On the other hand, there are a lot of Kennedys and they have a lot of kids. By my count, JFK has/had 11 nieces (and I might have missed some. That's a huge family) - so just as she is an (not "a") anchorwoman on tv, she's a niece of the former president.