The sentence describes teachers being placed between "children who are fighting." Since they are teachers, it is safe to assume they are attempting to stop the fights. "Arbitrators," meaning a mediator or the judge of a dispute, is the best answer choice.

The sentence notes two key facts, that the groups are "throughout the country" and that they have made "law enforcement highly concerned." The correct answer needs to indicate that the "terrorist groups" are spreading and disseminating, the definition of "proliferation."

The plan resembles "previously failed approaches," which makes people question the aspect described by the missing word. The correct answer needs to describe the plan's ability or function. "Efficacy," meaning effectiveness or usefulness, is the best choice among the answers.

There are two great clues to the best answer in the sentence: "derogatory" and "to refer to her assistant." The missing word describes a term that can refer to someone in a derogatory manner. "Epithet," meaning an appellation or a shothand byword, is the best choice among the answers.

The sentence notes that the "king" is the missing word, despite having "no real power." This means the correct answer will indicate symbolic meaning in the king's position. "Figurehead," meaning a nominal leader or de jure leader with little authority, is the best choice among the answers.

The sentence discusses "rival gangs" leaving a dance "at the same time." This means the correct answer should indicate a confrontation or violence. "Fracas," meaning a disturbance or fight, is the best choice among the answers.

The missing word describes the two positions "despite" the fact the two men had discussed the matter "for hours." This means that they were not very close to agreeing, and the correct answer will indicate this fact. "Dissonance, meaning disagreement or a harsh dischord, is the best choice among the answers.

The missing word describes a particular architecture detail, with a clue provided in the sentence. Since the object is "underneath the mantelpiece," the correct answer will fit this description. "Frieze," a decorative border of bas-relief art, is the best choice among the answers.

The sentence says readers have the missing word even though "the argument was complicated and he frequently used difficult language." This means the correct answer needs to indicate readers can still appreciate or follow the essay. "Gist," meaning the main point or general essence, is the best choice among the answers.

The sentence explictly notes that the room's decor "mirrored the occupant's boring life." This means the correct answer needs to be a synonym of "boring." "Drabness," meaning a dullness or muted tone, is the best choice among the answers.