This sentence clearly is contrasting Regina and her sister. Regina is a careful planner who seems to set out to do exactly what she plans. From what we can tell, she does not deviate from these plans.  A person who is impulsive is just the opposite of this. He or she follows his or her impulses (wishes or desires), often going from one thing to the next without much explanation. Now, this can seem to be irrational, but these two words are not quite the same. An irrational person can also be someone who just can't "think straight" because he or she is angry. An impulsive person is a closer contrast to Regina's personality.

The key word in this sentence is "shock." It is stating that a suggestion that is shocking is able to make people pay attention. Now, a violent suggestion can do this, but really that is more than is being said by the sentence. The word "outrageous" is much closer to "shocking." Something that is outrageous is shockingly "over the top." It is extreme.

The most important clue in this sentence is the clause, "fearing that he might be misunderstood if he were completely clear about the meaning of his words." Harry did not want to be unclear with his words. Therefore, he apparently wanted to spell out every detail, meaning that he wanted to be explicit in what he stated. When something is "implicit", it is unstated even if it is assumed. An explicit matter is discussed completely "in the open."

The key clue in this sentence is the fact that the argument being made in the book can't be found in any other books. This does not necessarily mean that the argument is controversial, though it might be.  Likewise, this doesn't mean that it is necessarily amazing—though such rare things are often amazing. Instead, it just means that it is a rare argument. Whenever something is so rare that it is not found anywhere else, it is "unique."

For this sentence, it is true that scientists must be attentive when they do their experiments. The point of the sentence, however, is most directly that they must avoid mistakes. This implies that they must be very "exact" with their measurements. They must not be sloppy but instead must try to find the measurement that is closest to reality as is possible.

Based on the description, this must have been a very stately dinner. It had a very elevated dignity and importance about it. Whenever something is "dignified", it is important and serious. This well describes the dinner, given the remarks made in the clause at the end of the sentence. Given all of the important people at the meal, it must have been a very serious, majestic, and dignified affair.

All that we know about the statue is that it is drawing people's attention. It might have been very "expensive," or it might have been very large ("massive"); however, we just don't know those details. All that we know is that the statue seems to be very interesting. When something is "intriguing," it draws attention and interest. Among the options provided, the word "intriguing" is the only one that expresses this general idea of being interesting.

A person who does not take risks may well not have much confidence in him- or herself. Such a person is called "timid." Often, timid people are afraid. In a way, this sentence is speaking of a fear of taking risks. Among the options provided, none of the others expresses exactly the kind of character someone might have when he or she is afraid of taking risks. Therefore, "timid" is the best option provided. Yes, "scholarly" people and even "religious" people can be afraid of risks; however, this is not always the case (nor even necessarily the case most of the time). A "timid" person, however, is almost certainly afraid of taking risks.

George's idea apparently made his brothers think that he was quite crazy. It must have been a crazy idea in itself—which is likely the case. When could someone ever buy a baseball team for five cents? Therefore, the idea could also be called "deranged." When we call something or someone "deranged," we are saying that he or she is insane or crazy.

All that we know about the flower is that it is plastic and fake-looking. We can't say anything about how expensive it looks ("cheap") or about its size ("miniature"). Therefore, the best option is "artificial." Something that is artificial is made up, not real,or not authentic. A plastic flower that is fake-looking can at least be called "artificial," if nothing else!