From the sentence, you can deduce that Laura's ultimate goal with her retorts is to get rid of the strange man talking to her, but she doesn't succeed until she changes tactics. Therefore, "amend" (improve) does not fit the context. And while the other for words are meant to lessen and/or stop the advances to various extents—"attenuate" (diminish), "palliate" (soothe), "discourage" (persuade not to do something), and "halt" (stop)—it is only the word with the strongest connotation, "halt," that matches the notion of "getting rid of for good." Thus, "halt" is the correct answer.

The superstar's actions when questioned made the media believe that she lied. Therefore, "duplicities" (lies) doesn't fit, as it's too strong for what amounts to suspicion. "Imitations" (copies) also doesn't work on a definition basis. We're left with "canards" (rumors with no basis), "articulations" (things that are said), and "prevarications" (indirect answers to a question allowing one to avoid telling the truth).  

While "articulations" could work, as her words could be leading the media to believe she is lying, it is not nearly as specific as the other two words. And while "canards" could also work, as her spoken rumors could lead them to believe she's lying, it's not as specific as "prevarications," which is directly related to lines of questioning. Thus, "prevarications" is the correct answer.

A tried-and-true approach to text completion questions is the process of elimination approach: get rid of answer choices first due to their definitions, then due to their connotations and intensities. On many questions, just the first part of the process will suffice, though on some, like this one, you will have to consider connotations as well.

First, we can get rid of "wandering" (traveling aimlessly) because the word doesn't make much sense in context. Then, we're left with "flabbergasted," "bewildered," "bemused," and "disbelieving," which all express some level of shock and/or confusion, an emotion that makes sense if a book's sequel is announced fifty years after it was published.  

However, it is here that you must pay special attention to context clues. The sentence explicitly states that "no one expected" the sequel, but says nothing about anyone being confused, caught off guard, or the like. There is simply surprise. Thus, the words that imply confusion—"bewildered" and "bemused"—can be thrown out. The sentence also doesn't explicitly state anything about skepticism, which "disbelieving" implies, at the very least. Thus, we are left with "flabbergasted," which is the correct answer.

This sentence indicates a kind of intensification. Many people seemed to think that Harry would merely be happy. The word "merely" provides the best indication that we want to describe him has being something more than "merely happy." A great intensifier for "happy" is "elated," which describes someone who is extremely happy.