In this sentence you are told that the student will stop at nothing to get what he wants. He is willing to work hard and has goals in mind that drive him forward. He is therefore "ambitious." "Ambitious" means driven, determined to reach certain goals. To provide further help, "selfless" means not selfish, generous; "apathetic" means uncaring; "quarrelsome" means argumentative, inclined towards fighting; "loquacious" means talkative.

If the subject had to call his father for help it makes sense that he found the instructions too difficult to understand. The correct answer then is "complex," which means consisting of many different parts and very hard to understand. To provide further help the other four answers are all antonyms of "complex," they all mean easy, easy to understand.

Based on the context of this sentence you are looking for something that matches with a "wet" day in which someone might be inspired not to get out of bed by the terrible weather. The correct answer then is "dreary" which means dull, uninspiring, and depressing. To provide further help, "lustrous" means shiny; "voracious" means not easily satisfied, greedy, having an immense desire to eat; "perpetual" means lasting forever; "coherent" means able to be understood.

The author is talking about his "failings" so it makes sense that his memory of them would be exasperating, annoying, or frustrating. These words are all synonyms of "vexed," which means annoyed by, confused and frustrated by. Additionally, "encouraged" means supported; "implored" means begged, urged; "beckoned" means summoned, called someone towards; "refuted" means argued against, disputed, proved wrong. 

The dogs in the shelter are "sick and malnourished" (under-fed), so it makes sense that they would have been treated with a lack of compassion, with cruelty. So, the correct answer is "inhumane," which means without compassion, cruel, malicious. Additionally, "posthumous" means after death; "perpetual" means eternal, lasting forever; "convoluted" means complex and hard to understand; "expensive" means costing a lot of money.

This sentence expresses a kind of intensification in its comparison of Laura and Paula. Paula apparently wants to kill every last bug in the house. A great word for this would be "exterminate," but that option is not given. The word "eradicate" expresses this notion of totally killing as well.  (Hence, it is better than "kill" or "destroy.") The word "eradicate" comes from Latin bases that mean, to take out the roots. Imagine if you were to rip out the roots of a tree. This would involve totally eliminating the tree.

Since the sentence says at the end that Vincent wanted to convince Jordan, we know that he must be asking him to stop his smoking and not forcing him to do so. Now, we also know that Vincent is doing this frequently. This hints that he is very worried and is asking his friend to stop in a very devoted manner. Whenever we implore someone to do something, we ask him or her regularly and earnestly to stop. This kind of asking is hinted at by the sentence, so "implore" is the best option.

This sentence indicates on several occasions that the teachers voice itself is very boring. We have words like "boring" and "droned" that make us think of a voice that is very tedious and unchanging. Whenever someone is "monotonous," he or she has a voice that does not change its pitch very much at all. The word comes from the prefix "mono-" and the stem "-tonous", meaning one-sounded. A monotonous voice can become very boring, very quickly, so it is understandable that the students in question fell asleep—even though the topic itself was interesting!

The two men apparently want to destroy the carpet with a fire. Now, it would be acceptable to choose "burn", but the word "incinerate" is just a little bit better of an option. It means, to destroy with fire. This is a little more accurate and detailed about just what the two men are doing.

This sentence implies a contrast between two kinds of facts. On the one hand, there are unimportant facts. There are many of these, and they do not help in solving many investigations. On the other hand, there are facts that are important and do help in solving cases. Whenever something is "crucial," it is very important. This is the only option that expresses this general idea about being "very important."