The key expression is the participial clause “feeling a perpetual state of sadness and depression.” While Isaac might be described in terms of any of the options given for this sentence, this phrase clearly indicates that he was saddened. When someone experience “melancholy,” he or she is sad and thoughtful. The word comes from the old theories of the “humors” (or blood chemicals) that were believed to influence psychological dispositions. Melancholy was believed to be derived from too much “black bile.” Someone who was bad-tempered was called “choleric” or “bilious”—a surprising but understandable relation, given the connection to bile. The word “cholesterol,” literally means “stiff bile” (though that is an inadequate medical definition, of course).

The implication in the sentence is that Elaine’s diet was based on the principle of picking the “middle road” in consumption—not too much, not too little. Such a plan is one of “moderation,” meaning one of “avoiding extremes.” It is related to words pertaining to the “middle,” and we can see rather direct relatives in words like “moderator”—a person who is supposed to enable two (or more) opposing parties to discuss some matter by means of this “middle party.”

The key word for the opposition expressed here is “reasonable.” The best option must mean “unreasonable” and not merely something like “crazy” (as do many of the options). While the word “irrational” is often used to describe someone who is angry or uncontrolled, it primarily means “acting without reason” or (even more directly) “not rational.” The latter sense is directly evident when you see the “ir-” prefix, which here means “not,” and the base of the word “rational.”

We know that the swimmer "discovered she had a fear of heights" at the top of the tall diving board, so we can infer that we need to pick out a word that describes an emotion and means something like "fear." While "rage," "ennui," "eagerness," and "trepidation" all describe emotions, only "trepidation" ("a feeling of fear or agitation about something that may happen") fits the context of the sentence. So, "trepidation" is the correct answer.

The key expression here is “unsaid premises.” The thing that is believed to have been revealed would be such premises, which would be called “presuppositions.” The word literally means “things supposed before (something else).” Often, such things often are not spoken and are merely presumed without much reflection.

This sentence is perhaps difficult, but pay attention to the role played by extravagance and the act of “seeing” done by those who come to the park. They come to see something that is quite impressive, even if there are no other reasons for them to come. When something is called a “spectacle,” it is something that is “quite a sight”—that is, an impressive sight. The word is related to words like “spectator” and “introspection,” as well as many other words implying “sight” in their “spect-” portion.

Although the sentence might seem strange, still it clearly states that Patrick had never experienced love at all; therefore, he cannot merely be said to have no opinion or assessment of it but instead must be said to have “no idea at all” concerning it. To this end, the word “conception” is the best option, for it can mean a “mental idea.” The word often is used to describe the process of becoming pregnant, but its older philosophical usage aligns more directly with the notion of the mind being united with the thing known, as is reflected in the literal translation from Latin: “to take (-ception) with (con-).”

Since the deed is described as being courageous, we know that Odo was not insane in his undertaking. Likewise, it does not make much sense to say that he showed his great fame or honor by undertaking the task, though he might have gained fame and honor thereby; therefore, “valor” is the best option, for it means “great courage” particularly when one has to face a dangerous situation. It comes from the Latin meaning “to be well, strong, or healthy” and is found in English words like “prevail,” “invalid,” and “valid.”

The key word here is “outlast,” for it implies that the commander hoped to wear down his foes with time. Although this could be considered an act of “patience,” the more appropriate word here is “attrition,” which means “to wear down” something through continual action. It is derived from the Latin for “to rub or wear” and is found in words like “contrite,” “contrition,” and “detritus.”

The best answer here is that which most closely describes a turtle’s defensive shell. The word “carapace” is a specific instance of external protective devices that some creatures have. While this is a defense or shield of types, the sentence’s comparison to the turtle makes “carapace” the best answer.