"Appropriate" means fitting, right, or suitable. To help you, "severe" and "intense" are synonyms of one another; they both describe something that is extreme. Also, "mediocre" means average when better-than-average was expected.

To "encapsulate" something means to surround it or include it. Think of a capsule of medicine; the capsule surrounds or includes the medicine inside it. So, "include" is the correct answer.

Resistant. Impervious most nearly means, impenetrable and impassable. Something that is "impervious" is resistant to certain or all things. For instance, a sentence using the word would be "He was impervious to her reasoning."

Most of the other choices are antonyms, with the exception of "nervous" which is unrelated.

The Latin prefix regu- means related to rules or law, as in "regime" which means government, a collection of rulers. So, to "regulate" means to enforce the rules, to control the actions of.

The word "radiant" comes from Latin roots that mean to send out rays. Think of X-rays. Such technology is so named precisely because these devices use waves or "rays" to detect bone (and other) structures in your body. There can be "rays of sun," meaning the sunlight itself, shining. Thus, when we say that something is "radiant," we mean that it is shining. This word can be used metaphorically meaning joyful, as we say something like, "He was radiant when his mother told him that he would have his favorite dessert that that night."

"Incontrovertible" is an adjective that means "not able to be denied or disputed," so we need to pick out an answer choice that means something like "undeniable." "Unbelievable," while beginning with a negative prefix like both "incontrovertible" ("in-") and "undeniable" ("un-") do, actually means "not able to be believed; unlikely to be true," so it is an antonym of "incontrovertible" and "undeniable." "Irrefutable," however, is an adjective that means "impossible to deny or disprove," and because "irrefutable" is the answer choice closest in meaning to "incontrovertible," "irrefutable" is the correct answer.

The word "salient" comes from a Latin word meaning to leap. If someone makes a salient point, it's as if that point is leaping out at you, leading to its meaning of prominent or relevant. Don't be deceived by false cognates, such as "saline" (salty), or "sale" (discounted).

To be "weary" means to be tired, so "weariness" is tiredness or exhaustion. To provide further help, "frankness" is honesty, often brutal honesty; "poverty" is the state of being very poor, the opposite of "wealth"; "hearsay" is gossip, unreliable information passed along within a group of people.

A "sage" is someone with a high level of wisdom or, in its adjectival form, "sage" means learned. Therefore, the best answer choice is "wise," since it is the direct definition of "sage." In terms of the other answer choices, "candid" means honest, "affable" means kindly, "altruistic" means willing to give generously, and someone who is "innocent" is naive in certain aspects of life.

Resistant. Impervious most nearly means, impenetrable and impassable. Something that is "impervious" is resistant to certain or all things. For instance, a sentence using the word would be "He was impervious to her reasoning."

Most of the other choices are antonyms, with the exception of "nervous" which is unrelated.