"Recalcitrant" means defiant or unapologetic.

A human being befriending a dinosaur is historically and scientifically incorrect, and "anachronistically" is the only answer choice that fits. “Anachronistically” means historically out of place.

While details could be "urbane," "recurring," "logistical," "grotesque," or "lurid," only "lurid" refers to the facts one would be most likely to find in a romance novel.

His position was difficult to hold or impossible to use to convince other people, thus it was "untenable." "Salibrous: can be crossed off immediately for not pertaining to a position, but instead to health. While he may be "entrenched" in this opinion, his relationship to the opinion is not in question. While "illusory" is a tempting option as it means not real, he is holding a real position; it is simply unable to be maintained or defended.

The answer must be an adjective that describes the noun "pigeons." "Plethora" is a noun that means a large group and "surfeit" is a noun that means excess. "Abundant" is the only adjective that suggests a large number, while "paucity" and "sparse" refer to a small number.

The person being addressed in the sentence seems to be making a big deal out of "trivial issues," meaning that "petty" is the correct answer. The other answer choices provide confusing contrasts to pettiness—such as "hyperbolic" (exaggerating), "childish" (immature), "commensurate" (proportional), or "maudlin" (overly sentimental).

Although solitary confinement suggests insanity or lack of social structure, the sentence is specifically describing the prisoner's body, not his mental state. We need an adjective with a negative connotation, so "enticing" makes no sense. "Incompetent" and "delirious," though they could describe a person after solitary confinement, would not be used to refer to the body. "Discordant," although possibly descriptive of a prisoner's state of mind or actions after receiving solitary confinement, does not describe the body. These answer choices are especially difficult because "weak" is the least complex vocabulary word in the answer choices.

From the use of the word “stature” you know that whatever attribute of Napoleon is being described it refers to his size. Of the five answer choices only diminutive is a word that describes the size of something. Diminutive means very small, and is the correct answer. Sagacious means wise; lupine means wolf-like or related to wolves; illuminated means to make something easier to understand.

From the context of the sentence you can see that the blank word must be closely related, or identical in meaning, to the word “wise.” Of the five answer choices sagacious most closely resembles this meaning. Sagacious means wise or shrewd. Remiss means careless or negligent; regressive means to take a step backwards towards a less developed condition.

The key word in this sentence is "unpredictable," which, when coupled with the way students avoid the professor, indicate that there is something unpleasant or disagreeable about him. "Cantankerous," which means ill-tempered or disagreeable, is the only answer choice with such a negative connotation.