“Meticulous” means very careful and diligent, especially with a particular project, so "diligent" is the correct answer. As for the other answer choices, “impolite” means rude; “extinct” means no longer in existence due to having died out entirely; "sly" means sneaky and full of guile; and "hazardous" means dangerous or having the potential to cause someone harm.

“Obdurate” means stubborn, intransigent, and not likely to change one’s mind, so "stubborn" is the correct answer. “Enlightened” means having a rational perspective and open-minded; "considerate" means thinking of other people's feelings when making decisions; “discerning" means perceptive and astute; “resolute” means determined, unwavering, sticking to something.

Someone who is “aloof” is emotionally distant and detached from others, so "detached" is the correct answer. As for the other answer choices, “attached” means connected to; “distracted” means having one's attention taken by something other than what one is are focused on; “attracted” means drawn towards; and “familiar” means well-known to you.

“Cantankerous” means surly and ill-tempered, so "crotchety," which means irascible, is the correct answer. As for the other answer choices, “elegant” means sophisticated; “extraneous” means more than what is unnecessary; “grieving” means mourning the loss of something or someone; “grim” means uninviting, harsh, and depressing.

"Pugnacious" derives from the Latin for "to fight," so it makes sense that "pugnacious" means eager to fight, argumentative, or "quarrelsome." As for the other answer choices, “merciless” means having no mercy, not stopping for anyone, relentless, and ruthless; “diaphanous” means transparent, very delicate, and fine; “insincere” means dishonest; and “opaque” means not transparent and blocking light from passing through.

“Mutable” means subject to change or "changeable." As for the other answer choices, “invariable” means unchanging; “audible” means able to be heard; “sensible” means reasonable and making good decisions; and “unreasonable” means not based on good sense and logic.

Someone who is “magnanimous” is generous and charitable, or "benevolent." As for the other answer choices, “malevolent” means wicked and unkind; “colloquial” means conversational or using language unique to a certain region; “incoherent” means unable to be understood; and “submissive” means listening to others and doing what they want without arguing.

A “skeptical” person is doubtful, unconvinced, or "cynical." As for the other answer choices, “gullible” means easily tricked; “expressive” means showing emotion, inclined to express themselves, or not reserved; “reflective” means thoughtful, introspective, and thinking about things; and “nostalgic” means fondly remembering the past.

“Venerable" means distinguished, eminent, and deserving intense respect, so "eminent" (widely known and respected for achievements and work in some specific area) is the correct answer. As for the other answer choices, “dilapidated” means in a state of disrepair or falling apart; “obligatory” means required; “perverse” means showing a desire to do something undesirable; “sophisticated” means elegant and cosmopolitan or complex and advanced.

“Lax” means negligent, not giving enough attention to something, or not taking something seriously enough, so "negligent" is the best synonym amongst the answer choices. As for the other answer choices, “odious” means unpleasant, revolting, or disgusting; “prolific” means able to produce a large quantity of something quickly; “tedious” means dull and boring; and “remorseless” means not feeling guilty about one's actions.