"Obdurate" means pigheaded or stubborn. "Antediluvian" means out-of-date or prehistoric (ante=before, diluvian=the flood). "Bucolic" means rural or rustic in nature. "Didactic" means educational or explanatory. "Palpable" means clear or obvious. 

"Querulous" means habitually complaining or whining. "Recalcitrant" means stubbornly defiant. "Taciturn" means reserved or uncommunicative. "Venerable" means revered or sacred. "Nonchalant" means casual or unconcerned.

"Taciturn" means reserved or uncommunicative. "Gregarious" means outgoing or sociable. "Imperial" means majestic, noble, or proud. "Lugubrious" means depressing or somber. "Myriad" means multiple or various. 

"Inchoate" means undeveloped or beginning. "Myopic" means nearsighted or biased. "Lackadaisical" means careless or indifferent. "Hackneyed" means cliched or corny. "Fetid" means foul or rancid.

"Tenuous" means delicate or flimsy. "Indelible" means indestructible or enduring. "Pragmatic" means sensible or practical. "Intractable" means difficult or incurable. "Culpable" means responsible, liable, or guilty.

"Futile" means hopeless or pointless. "Venturesome" means courageous or adventurous. "Tranquil" means calm and peaceful. "Sodden" means saturated or drenched. "Nefarious" means horrible or sinful. 

Had this student actually completed seven degrees she could make the argument that her academic life was "prodigious" (which describes something that is enormous or exceptional). And one could attempt to argue that she "incessantly" (without ceasing) changed majors. But the best answer here is "fickle" (changing frequently; not particularly loyal or reliable).

Most people compose text messages using language that is more informal and conversational than the language they might use in a formal essay for school—instead of asking a friend, "Would you do me the honor of dining with me this afternoon?" you might simply text (more "colloquially"), "hey—let's get lunch." Thus, "colloquial" (language used in casual, everyday situations) is the best answer here.

You can hear the root meaning of joke within the word "jocular" (though it is pronounced not with the long O of "joke," but "JOCK-yuh-ler"). We learn here that Chris is rarely serious and that his personality provides welcome relief on difficult days. "Jocular" (joking and playful) is the best answer choice to describe him.

The sentence sets up a contrast: the critic prefers "modest" colors, but the exhibit presents the opposite. We know this because the critic "disapproved of the . . . neon colors," and we were told what the critic prefers: "modest earth tones." What word best fits the opposite of "modest earth tones" and matches with "bright neon colors"? We should predict that we need to pick out a word that means something like bright and colorful. "Subtle" means understated or cunning, which is the opposite of the word we predicted. "Frequent" means occuring often, and doesn't fit the sentence. The best fit is "garish," which means gaudy or glaring and is closest to our prediction of bright and colorful, though it describes something that is too bright and colorful.