We know that the people discussed in the sentence "usually assume that the writing of [thank-you] notes is compulsory for everyone else as well." So, we can infer that the people discussed think that writing thank-you notes for gifts is compulsory, and we need to pick out an adjective that means something like "compulsory." "Unimportant," then, cannot be the correct answer, because "unimportant" means "lacking in importance or significance," and wouldn't make sense in the blank. "Obligatory," however, is an adjective that can mean "required by a legal, moral, or other rule; compulsory" or "so customary or routine as to be expected of everyone or on every occasion," and because "obligatory" best describes how the sentence's subjects feel about hand-written thank-you notes, "obligatory" is the correct answer.

We can infer that after six failed attempts at solving the math problem, Sally must have felt a bit annoyed. So, we need to pick out an answer choice that means something like "annoyed." "Successful" cannot be the correct answer because it would not make sense in the blank; one would not likely feel very successful after six failed attempts at solving a math problem. "Frustrated," however, when used as an adjective, means "feeling or expressing distress and annoyance, especially because of inability to change or achieve something." Because "frustrated" best describes how someone would probably feel after failing to solve a math problem six times, "frustrated" is the correct answer.

We can infer that because Carolyn “had to stay home from school because she had the flu,” that we need to pick out an adjective to describe her that means something like “sick.” That means that “robust” cannot be the correct answer, because “robust” is an adjective that means “strong and healthy,” making it an antonym of the word for which we’re looking. “Indisposed,” however, is an adjective that can mean “unwell,” and because “indisposed” best fits the context of the sentence, “indisposed” is the correct answer.

In terms of public speaking, Natasha was anxious about public speaking and therefore she was flustered when she began to speak; in other words, she was nervous and slightly agitated.

We know that Kim expected the bill to be smaller, so we should pick out an answer choice that means something like "shocked." Since "stupefied" means "astonished and shocked," "stupefied" is the only answer that fits the context of the sentence, so "stupefied" is the correct answer.

We can tell from the context of the sentence that people expected Liam to be injured, but he somehow remained unhurt, "with not even a bruise or scrape." So, we need to pick out an answer choice that means something like "unhurt." While "unscathed," "unburnt," and "unparalleled" may all look like potentially correct answers, the meaning of "unparalleled"("unequalled") doesn't have anything to do with injuries, while "unburnt" specifically refers to injuries that are burns, which doesn't fit the context of the sentence. "Unscathed," however, means "without suffering any injury, damage, or harm," and best fits the context of the sentence, so "unscathed" is the correct answer.

We know from the sentence's context that all of the group's members voted for Sarah to be the leader, even though she expected a few people to disagree and vote differently. So, we know that all the members voted the same way, and need to pick out an answer choice that reflects this. While "unambiguously" and "unanimously" might both look like potentially correct answers, "unambiguously" means "clearly" or "not open to more than one interpretation," it doesn't quite fit the context of the sentence. However, "unanimously" means "without opposition; with the agreement of all people involved," and because "unanimously" best fits the sentence's meaning, "unanimously" is the correct answer.

Because the sentence discusses the moment when the band "walked out onto the stage…before beginning their first song," we know that it is discussing the beginning of the concert. So, we need to pick out an answer choice that means something like "began." "Ended" and "concluded" both refer to the end of something, so neither of them can be correct, "proceeded" means "continued" so it cannot be correct either, and "deferred" has nothing to do with chronological progression like the other answer choices do. "Commenced," however, means "began; started," so "commenced" is the correct answer because it best fits the context of the sentence.

We can infer that because the artist's pottery involves "bright cerulean blue, sunflower yellow, and intense red," that she is known for her bright colors. So, we need to pick out an answer choice that is an adjective that refers to colors and means something like "bright." So, "drab" cannot be the correct answer because "drab" means "lacking brightness or interest; drearily dull," so "drab" is an antonym of "bright" and does not describe the bright colors the artist uses. "Vibrant," however, when describing color, means "bright and striking," and because it is the answer choice that best describes the bright colors that the artist uses and best fits the context of the sentence, "vibrant" is the correct answer.

The sentence tells us that "one couldn't miss [the warrior's scar] when looking at him and it was rather hard to ignore," we can infer that it was very obvious. So, we need to pick out an answer choice that is an adjective that means something like "obvious" and describes physical features. So, "subtle" cannot be the correct answer because in this context, "subtle" means "hard to notice or see; not obvious," so it is an antonym of "obvious." "Prominent," however, is an adjective that means "important; famous," "projecting from something; protuberant," or "situated so as to catch the attention; noticeable." Because "prominent" is the answer choice that best describes the warrior's scar and best fits the context of the sentence, "prominent" is the correct answer.