"Robust" means strong, durable, or sturdy, so "sturdy" is the correct answer. None of the other answer choices are close in meaning to "robust": "timid" means easily scared and frightened; "flexible" means pliable or able to bend easily; "miserable" means depressed and unhappy; and "frequent" means occurring often.

"Opaque" means non-transparent or unable to let light pass through and thus be looked through. Something that is "cloudy" is not see-through; therefore, "cloudy" is the closest synonym because something that is cloudy is not see-through, and hence is non-transparent. None of the other possibilities mean "non-transparent." While "opulent" sounds similar to opaque, it has a different meaning: wealthy. As for the other answer choices, "disgusting" means unpleasant to the senses or gross, and "powerful" means possessing power or strong.

If something is ornate, it means that it is decorative or detailed.  An example of this is there may be an ornate artistic design that an artist chooses to use in a painting.

Although there is a verb form of "lavish," this question refers to the adjectival form of the word "lavish." Thus, the word "lavish," as used in the phrase "lavish spending," is closest in meaning to the word "extravagant."

“Anemic” means sick-looking or weak, and as such, it is closest in meaning to “pale,” which means lacking color or looking sick. To provide further help, “haughty” means boastful and arrogant; “tanned” means darkened by the sun; “anxious” means worried; and “modest” means not haughty or humble. 

"Arid" is an adjective that means "having little or no rain; too dry or barren to support vegetation" when it refers to land or climate, or "lacking in interest, excitement, or meaning" in referring to other things. So, we need to pick out an answer choice that means something like either "dry" or "boring." While "airy" may look like a potentially correct answer choice because it is similar in spelling and pronunciation to "arid," "airy" does not mean "dry" or "boring," so it cannot be the correct answer. "Dry" is the answer choice closest in meaning to "arid," so it is the correct answer.

Something that is "appetizing" is something that makes one want to eat. The answer choice closest in meaning to "appetizing" is "tempting," which means enticing or appealing, even though enjoying it might be a bad idea or wrong, so "tempting" is the correct answer.

"Delectable" means tasty or delicious, so "tasty" is the correct answer. To help you, "circumstantial" means accidental or owed to circumstance, "outrageous" means ridiculous, "ubiquitous" means ever-present or everywhere, and "surrogate" means substitute, stand-in, or replacement.

"Combustible" means explosive, while "volatile" means liable to change or explode. Thus, "combustible" is closest in meaning to "volatile."

Someone or something that is "robust" is strong and sturdy, so "strong" is the correct answer. To help you, "timid," "shy," and "introverted" are all loose synonyms of one another. Someone who is "timid" is shy and weak, and someone who is "introverted" is shy, reserved, and quiet.