Nearly all of the answers provide a decent option for the second word (with the exception of "berated," which does not fit, as it means criticized in a nasty way).  The best way to approach this question is to notice that we are not really given any clues regarding exactly what Clint did. We only know that it was something that could be heard and that he had a positive disposition. Therefore, it is best to stay with the safe option, namely "optimism," which indicates that Clint always looked for the positive aspect of things. While "optimism" does indicate a general temperament (like angry describes a temperament), we can imagine that one can hear "optimism" insofar as one hears the optimistic remarks, jokes, opinions, and so forth that are made by an optimistic person.

The sense of the sentence is that the meeting “fell apart,” going form a serious discussion to one of mere laugher. When something is serious, it can be called “grave,” in the sense of “having weight.” (When someone has “gravity” or “gravitas,” it is implied that such a person does not just pass from one opinion to another in a light-hearted manner). When things “devolve,” they literally are said to “roll downward” or (more directly in English) to “degenerate.” The “-volve” portion of the word is the same as that founding “revolve” and “evolve.”

For the first blank, we need to pick out a verb that means something like "begged," because we can infer that the peasants are begging the prince to lower taxes so that they can continue to afford food. Either "implored" ("begged someone earnestly or desperately to do something") or "importuned" ("ask (someone) pressingly and persistently for or to do something") could be correct. For the second blank, we need to pick out a word that means something like "food," because it is described as being "a bit of wheat flour and a cup of vegetable soup per day." Either "sustenance" ("food and drink regarded as a source of strength; nourishment") or "nourishment" ("the food or other substances necessary for growth, health, and good condition") could be potentially correct. Of the possible words that we've identified as potentially correct for each blank, only "implored" and "sustenance" appear in the same answer choice in the correct order, so the correct answer is "implored . . . sustenance."

For the first blank, we need to pick out a word that describes a topographical feature that can have "a stream [running] through it on the valley floor." Because of the mention of a valley, "peak" cannot be the correct answer, and because of the mention of a stream, neither "desert" nor "ocean" make sense. Either "glen" ("a narrow valley") or "canyon" ("a deep gorge, typically one with a river flowing through it) could be potentially correct. For the second blank, we know that there are mountains on either side of the land feature, so either "enclosed" ("closed in, surrounded") or "bounded" ("bound" meaning "form the boundary of; enclose") could be the correct answer. Of the possible words that we've identified as potentially correct for each blank, only "glen" and "enclosed" appear in the same answer choice, so the correct answer is "glen . . . enclosed."

We can infer that for the first blank, we need to pick out a noun that means something like "look," because it is described as "mischievous" and it "appear[s] in her eyes." Either "gleam" ("of an emotion or quality: appear or be expressed through the brightness of someone's eyes or expression") or "spark" ("a trace of a specified quality or intense feeling") could be potentially correct. For the second blank, we need to pick out a verb that means something like "stop," because while the male subject "knew that they were going to get into trouble," he could not stop "such an outcome." Either "prevent" (" keep (something) from happening or arising") or "preclude" ("prevent from happening; make impossible") could be correct. Of the possible words that we've identified as potentially correct for each blank, only "gleam" and "prevent" appear in the same answer choice in the correct order, so the correct answer is "gleam . . . prevent."

For the first blank, we know that the specified patients were "kept away from the others," so we need to pick out a verb that means something like "kept away from others." Either "quarantined" ("imposed isolation on (a person, animal, or place); put in quarantine") or "isolated" ("caused (a person or place) to be or remain alone or apart from others") could be correct. For the second blank, we need to pick out a noun that means something like "a contagious disease," because we know that "the doctors suspected that disease that they were all suffering from could . . . infect everyone in the surrounding area if proper precautions were not taken." Either "epidemic" ("a widespread occurrence of an infectious disease in a community at a particular time") or "outbreak" ("the sudden or violent start of something unwelcome, such as war or disease") could be correct. Of the possible words that we've identified as potentially correct for each blank, only "quarantined" and "epidemic" appear in the same answer choice, so the correct answer is "quarantined . . . epidemic."

Both the young and the old (in this sentence at least) are not likely to believe. While there are differences, they both wait for answers before giving their belief to an assertion. The best words therefore, are “credence” and “assenting.”

The former is derived from the Latin credere, which means “to believe.” There are many English derivatives from this Latin base, such as “credible” and “creed.” “Assent” is derived from the Latin sentire meaning “to perceive” or “to feel.” It has the prefix “ad” (to / toward – as in “advance”), which becomes “as” when tagged onto “sentire.” There are many related words, not only using the prefix “ad” but likewise “sentire,” such as “sensitive,” “consent,” “consensual,” and “sentimental.”

Each generation brings forth a next generation, leading to the mentioned repetition. The best option is therefore “beget . . . circuit.” To “beget” means to bring forth often with the connotation of procreation. A “circuit” is a closed loop, therefore well filling the need of the second blank in this sentence.

There is something of a play on words in this sentence. The roommate has two sides, and “duple” (and related words) imply twoness, hence “duplicity.” This likewise means—and this is closer to our usage here—being deceitful (as in being “two faced”). To “evince” is to reveal a reality. Such an act need not show a heretofore hidden reality. One’s (e.g.) body motions “evince” (in the sense of “giving evidence for”) one’s caring nature. 

Since the concern here is with removing something that seems to increase the time of an undertaking, such an intervening object is an “impediment,” which means an obstruction.  To “expedite” something is to make it occur more quickly. Both words come from the Latin word for “foot” (This is reflected in the “-ped-” portion of the stem, not to be confused with the “ped” in words like “pediatric” and “pediatrician,” which have different roots). An “impediment” is something placed on (im+) the foot (so to speak), and to “expedite” is to remove something from the foot or away from its path (at least taken literally).