"Additional" means extra.

If something is “devoid,” it is being without a usual or expected attribute or accompaniment, so a “devoid” landscape could mean that it is lacking trees or life. If something is “barren,” it has very few plants or is not suitable for plants,so it is similar in meaning to “devoid.” “Devoid” is related to the root word “void,” which means empty space.

“Piddling” means small or unimportant. “Lilliputian” also means small; it comes from the book Gulliver's Travels and began to be used in language in the early 1700s. To help you, the suffix “-ous” means characterized by. “Gauche” means unpolished, clumsy, or inelegant. “Humongous” means extremely large. “Fungous” means the same as fungal.

“Abysmal” is an adjective that means “extremely bad; appalling,” so we need to pick out an answer choice that means something like “extremely bad.” That means that “phenomenal” cannot be the correct answer, because “phenomenal” is an adjective that can mean “very remarkable; extraordinary,” making it an antonym, not a synonym, of “abysmal.” “Deplorable,” however, is an adjective that can mean “shockingly bad in quality,” and because “deplorable” is the answer choice closest in meaning to “abysmal,” “deplorable” is the correct answer.

Something that is “exquisite” is beautiful and perfect. For clarification, "pliable" means flexible, and "haughty" means proud or self-important.

"Banal" means trite, cliché, and unimaginative; as such, it is most similar in meaning to “unoriginal.”

"Decent" means satisfactory. "Insufficient" means lacking in quantity and "unreasonable" means not reasonable, as one can infer from the word being a combination of the negative prefix "un-," which means not, and "reasonable." As for the other answers, neither of them are close in meaning to "decent": "familial" means of or relating to family, and "insane," being a combination of the negative prefix "in-," which means not, and "sane," means not sane, or suffering from a severe mental illness.

Opulent means luxurious or excessive and as such is most similar in meaning to “lavish," which can mean luxurious, plentiful, or describe the act of generous giving. "Eminent" means well-known or respected, and "authoritative" means controlling or displaying leadership.

"Optimal" is an adjective describing a noun that is the best or as well-suited to something as can be. Of the answer choices, "ideal" has the closest meaning. 

“Ramshackle” means in very poor condition, so we need to pick out an answer choice that means in disrepair. That means that “pristine” cannot be the correct answer, because “pristine” is an adjective that can mean, spotless, perfect, or in something's original condition making it an antonym, not a synonym, of “ramshackle.” “Dilapidated,” however, is an adjective that is used of a building or object and means in disrepair, and because “dilapidated” is the answer choice closest in meaning to “ramshackle,” “dilapidated” is the correct answer.