The most important part of the sentence for finding the correct answer is the fact that the missing word bears little relation to the plot. The correct answer should indicate some kind of diversion from the main thrust of the novel. Of the answer choices, only "tangents," meaning unrelated diversions from the subject, has the appropriate sense.

The two nations apparently had repressed their “antagonism” during the decades mentioned. Antagonism is the state of striving against someone or something, coming from the roots “anti-” and “agonia.” The latter, literally means struggle or contest. Its meaning has been extended in a word like “agony” in English (though, a person in agony is often struggling against that which is causing the agony); therefore, the two nations were hostile to each other, though it was repressed.   Such a state is called “hostility,” coming from the Latin “hostis” meaning either “stranger” or (more appropriate for our case) “enemy.”

Since the earthquake left almost nothing in the city, it was not merely empty but was instead utterly “desolated.” The word comes from the Latin meaning “completely alone.” The “de-” here takes on the sense of “completely,” and the “-solation” comes from “solus,” meaning “only or alone.” The latter is found in words like “solitary” and “solo.”

Although we might wish to say that the secretary’s action is “unbecoming” or perhaps even “absurd,” the word “extravagant” is best, for it is often used with the further implication of overstepping the bounds of propriety with regard to money. The word itself literally means “to wander outside of” some implied boundaries. The familiar prefix “extra-” means “outside of,” while the “-vagant” portion of the word is related to English words like “vagrant,” meaning one who wanders from place to place (often out of poverty).

The key word in this sentence is "plane." That simple context should lead you instantly to "hangar," which has the specific meaning of a building that houses planes.

The two key words are “complacency” and “laziness.” This implies a particular slowness and lack of effort. When one “saunters,” he or she walks in a slow and somewhat lazy manner—as on a slow walk down the trail.

In this sentence, it is really a matter of knowing the vocabulary, though you can likely eliminate several options as being a bit too limited. The most tempting wrong answers are both “contribution” and perhaps (if one thinks too much) “waiver.” Strictly speaking, the latter would imply more than what is said in the sentence. Against the option of “contribution,” the word “stipend” is better, as it means “a fixed salary, payment, or allowance.” “Contribution” is more vague than “stipend,” and therefore is less acceptable.

If something is “anachronistic,” it does not really belong in its given time period. Sometimes, the adjective can merely mean that something is old-fashioned, but it often is used to indicate the situation when someone describes something in one time period according to the customs or historical contingencies of another period. The prefix “ana-” comes from the Greek preposition meaning “backward” (among other things). The familiar “-chronistic” comes from the Greek word for time and has familiar English derivatives (such as “chronological”).

While “dilettante” may be related to the sentence and appear a potential choice, it indicates a person who cultivates an area of interest, such as food, but without any real commitment, only dabbling in it. The sentence indicates that the person in question has a knowledge more extensive than the rest of the group, so “epicure” is the more suitable answer choice.

A "cacophony" is a clamor or harsh noise, which is implied by "disruptive" and "resonating."