QUESTION EXPLANATIONS

1. (A) — The majority of the passage is dedicated to an account of the search for Mark and the concerned reactions of Audrey, Elsie, and Mrs. Stevens to a mysterious gunshot. (B) is incorrect because nobody actually sees a rabbit hunt; Audrey merely thinks that the gunshot was part of such a hunt. (C) is incorrect because although the first paragraph does describe “the Temple,” Mark’s summerhouse, there’s nothing in the passage about Mark criticizing his employees. (D) is incorrect because, while the housemaids do hear a gunshot and hide in a bedroom, they don’t appear to be hiding from Mark.

2. (C) — An “omniscient observer,” is the best way to describe the narrator. This passage isn’t clearly written from any single perspective; the narrator has access to Audrey’s thoughts (e.g. l. 20-26) as well as Elsie’s (l. 65-66), but doesn’t use the first person at all. Thus, we can assume that the narrator isn’t a character in the passage, but an omniscient, or all-seeing, observer. (A) is incorrect because the narrator is neither obviously physically present for the events described nor clearly frightened. (B) is incorrect because “meticulous analyst” suggests a person who’s actively trying to solve something; this is not true of the narrator, who merely reports without analyzing. (D) is incorrect because there’s no evidence that the narrator is either bored or a guest at the house.

3. (B) — In context, “retiring” is used to describe Mark going to the office after leaving from the Temple to “put his thoughts upon paper” (l. 5). The best answer choice is thus “retreating,” which conveys the idea of going towards a place of privacy and seclusion. (A) is incorrect because “deteriorating” suggests falling apart, or getting worse, but there is no evidence that anything negative happens when Mark goes to write in his office. (C) is incorrect because the word “discharging” tends to mean either setting something off (like a weapon) or formally removing someone from a position (as in the military expression, “honorable discharge”). In the context of Mark’s work habits, neither of these words describe what is taking place in the passage. (D) is incorrect because to “surrender” means to yield to an opposing power, which is not present in this part of the passage.

4. (C) — Here, “ordinary” describes the behavior of certain houseguests, behavior that Mark views as “careless”, and that causes him to feel “pained” (lines 10-11). It therefore means “distasteful” in the sense of rude or uncouth. (A) is incorrect because the word “natural” tends to mean something that is have either a neutral or a positive connotation, whereas the actions of the houseguests here are negative. (B) is incorrect because there is no evidence that the activities are “boring” in context. (D) is incorrect because “commonplace” suggests something that happens frequently and without obstruction; there is no indication that the Temple is often used for these kinds of activities, and surrounding negative words like “carelessly” and “offenders” strongly suggest that Mark views “flirtation and smoking” as specifically negative.

5. (D) — In lines 10-11, Mark is said to feel “a little pained when a visitor treats the Temple carelessly,” and then the narrator provides three examples of what Mark deems to be inappropriate or “careless” use of the Temple: flirtation, smoking, and playing hand-tennis. Once Mark asks two guests playing hand-tennis in The Temple to play somewhere else, there is little doubt that he views the Temple as a place for writing (as in line 5) and not for rowdy or social activities. (A) is incorrect because although the passage indicates that some guests were never invited to The Red House again after playing hand-tennis in the Temple, there is no indication that the Temple was off-limits to guests and visitors. (B) is incorrect because there is never any mention of the Temple’s appearance or how Mark feels about this, therefore there is no evidence to support any opinion Mark might have on how the Temple looks, or how up-to-date it is. (C) is incorrect because no family members of Mark’s have been mentioned yet, so it is impossible to infer that part of Mark’s property has been reserved for this reason.

6. (B) — The quoted portion follows the information that Mark likes to meditate in the Temple, but condemns those who participate in more rowdy activities there, proving that Mark sees the Temple as primarily for quiet activities. (A) is incorrect because the portion merely describes where the Temple is located. (C) is incorrect because the quoted portion is about the specific behavior of two guests, not Mark’s feelings about the Temple. (D) is incorrect because the quoted portion relates to Audrey’s search for Mark rather than his feelings about the Temple.

7. (D) — The line, “Bangs and explosions and terrible things” raises a new possibility in the story, that of a violent or dangerous act “inside the house” (lines 46-47) taking place instead of the rabbit hunts the maids are used to hearing. (A) is incorrect because there’s no evidence in the passage of Mrs. Stevens’ extensive knowledge of guns. (B) is incorrect because the passage doesn’t take a stance against hunting, and Mrs. Stevens isn’t referring to hunting. (C) is incorrect because there is no evidence anywhere in the passage that Mrs. Stevens is involved with any crime.

8. (A) — The evidence in lines 52-61 suggests that Audrey and Mrs. Stevens think Mark’s brother is suspicious and impolite. He is called “rude” and Mrs. Stevens states that “there [is] no use speaking with anyone from Australia.” Further evidence comes from the correct answer to question 9. (B) is incorrect because there’s no evidence for the brother’s wealth. (C) is incorrect because the things Audrey and Mrs. Stevens say about the brother directly contradict this idea. (D) is incorrect because, once again, the two women do not actually say these things about the brother.

9. (C) — Here, Audrey recounts her first reaction to the brother, which is that he seemed like a “bad lot.” (A) is incorrect because the passage doesn’t relate to the brother directly; it merely indicates that Elsie was frightened. (B) is incorrect because the portion states that it sounded like the men were shooting rabbits, but again does not relate to the brother. (D) is incorrect because the statement relates to Mrs. Steven’s feeling of fear rather than her direct assessment of the brother’s character.

10. (A) — Elsie responds to Mrs. Steven’s statement of fear with her own needs in mind; in other words, she is not focused on the current, potentially dangerous situation. (B) is incorrect; it may be true of Elsie, but it is not the focus of the scene, and there is no evidence that it is true of the other housemaids. (C) is incorrect because there’s no evidence here of Elsie’s “initiative,” meaning special preparedness or alertness. (D) is incorrect because physical appearances aren’t the focus of the scene.

11. (C) — The passage’s focus is to investigate the hypothesis that plastic which smells like DMS causes seabirds to mistake it for food. (A) is incorrect because the author only vilifies DMS by explaining that it indirectly causes more plastic consumption, not that it is dangerous (chemically or otherwise) on its own; in fact, under normal circumstances, DMS seems to be an important signal for tube-nosed seabirds that there is food nearby, as in lines 49-51. (B) is incorrect because the author only mentions seabird species going extinct briefly in one paragraph,so extending this idea to all species is an extreme conclusion that the passage does not reach for. (D) is incorrect because although the author indicates that studying DMS has helped his understanding of seabirds, the passage never claims that this knowledge is applicable to marine life in general.

12. (A) — This option is centered around ingesting something dangerous because it is mistaken for food, which matches the problematic behavior of the seagulls. (B) is incorrect because the subject knowingly alters his diet to improve his health, while the seagulls in the passage are not aware their diet is changing, and even if they were, this change is detrimental to their health, not beneficial. (C) is incorrect because the harmful food is being eaten even though the subject knows it is harmful, while the seagulls are ignorant of the harm their diet is causing them. (D) is incorrect because the seagulls are unfortunately not fearful of eating plastic.

13. (C) — The author explains the biofouling process in line 70 before stating that it produces DMS, which matches the statement this answer option makes. (A) is incorrect because the passage claims that plastic gets its DMS-smell from algae coating it, which has nothing to do with the nature of the plastic itself. (B) is incorrect because the passage does not offer any information about why krill or other seabird prey ingest plastic. (D) is incorrect because the passage explains that plastic smells like DMS specifically when it is submerged in water and coated with algae, so it wouldn’t make sense to assume that “all” plastic smells like DMS.

14. (D) — This quote states that the plastic submerged in water by the author was coated with algae (which, as the author states, are instrumental in the biofouling process) and contained large amounts of DMS, which backs up the claim of the correct answer to the previous question. (A) is incorrect because it explains what happens to plastic at sea, not how it relates to the biofouling process or DMS, which the previous question’s correct answer claims. (B) is not correct because a list of seabird prey and a claim that perhaps seabirds think plastic looks like their prey is not related to biofouling or DMS. (C) cannot be correct because this quote specifies that seabirds are attracted to the krill eating algae, not the algae themselves, instead of discussing the production of DMS.

15. (D) — The fact that seabirds are going extinct functions as reasoning for why their ingestion of plastic is a serious issue, because the author communicates that consumption of plastic is deadly for seabirds, for example in lines 8–11. (A) is incorrect because nowhere in the passage does the author communicate any feelings of concern towards endangered species in general. (B) is incorrect because the author never explores why animals generally go extinct, and the mere mention of one species’ near extinction is not enough to infer the author’s beliefs about extinction on such a broad level. (C) is incorrect because expressing that tube-nosed seabirds are at risk of extinction does not independently lead to a reason why they are going extinct, which this option states.

16. (A) — The author conducts his experiment of submerging plastic in the ocean, which he hypothesizes will attract algae and algae-grazers, and then tests to see if it smells like DMS. His results match his hypothesis, which lends credibility to the argument that DMS-responsive seabirds eat plastic because it smells like food. (B) and (C) are incorrect because the author never interviews any marine biologists, or introduces any academic reports on where seabirds find their food. (D) is incorrect because while the chemical composition of DMS is briefly mentioned, no actual studies are referenced.

17. (D) — The author explicitly states in this quote how the results of his experiment support his hypothesis. (A) is incorrect because this quote only deals with an assumption about why seabirds eat plastic, which the author does not use to back up his arguments. (B) is incorrect because it only contains information about when it was discovered that certain seabirds use smell to hunt; this is not an experiment, nor does it feature results the author found that support his argument. (C) cannot be correct because this statement only describes part of the author’s process while conducting his experiment, not his results.

18. (B) — The word “forage” in this passage describes the actions of the seabirds as they seek out food for their survival, which is synonymous with “hunt”. (A) is incorrect because in order for the seabirds to “chase” their prey, their prey would have to be running away from them, which the author never claims they do. (C) is incorrect because the seabirds are only interested in the food that is in the ocean, not curious about what the ocean contains or looks like, which “explore” implies. (D) cannot be correct because the word “ransack” implies that the seabirds are harming the ocean as they search,which the passage never describes them doing.

19. (B) — In the context of the passage, “cue” is being used to describe the way that DMS attracts foraging seabirds; both “cue” and “signal” are actions which are used to draw attention to a wanted object or preferred action . (A) is incorrect because to “nod” usually includes the physical act of nodding your head to communicate a stance, which would be impossible for DMS to do. (C) is incorrect because “warning” means to communicate approaching danger so that others may avoid it , while “cue” is being used in this passage to signal the presence of food, which, to seabirds, is something they want to encounter, not avoid. (D) is incorrect because “suggestion” is the presentation of one possible action that is thought to be beneficial, while to “cue” is to communicate that a definite, desired behavior should take place.

20. (D) — The darker bars, which represent the seabirds that do not detect DMS, are far smaller than the lighter bars representing the seabirds that do detect DMS, meaning they consume less plastic because of this distinction. (A) is incorrect because the graph shows that different species of seabirds consume different amounts of plastic, which opposes what this option claims. The graph does not give information about seabirds’ responsiveness to DMS over time, so (B) and (C) are incorrect.

21. (C) — The graph shows that DMS-responsive seabirds ingest more plastic than non-DMS-responsive seabirds, and the passage pays significant attention to how DMS is emitted by algae on plastic, attracting seabirds who will consume it. (A) is incorrect because the author states another reason seabirds ingest plastic: it looks like their prey. (B) is incorrect because the passage never discusses which DMS-responsive seabirds are best at detecting DMS. As well, the graph only shows how much plastic certain seabirds ingest, not which seabird best detects DMS. Although certain DMS-responsive species are more likely to ingest plastic than others, the graph doesn’t explain why this happens, so there is no evidence that the puffinus tenuirostris, for example, is better at detecting DMS than the Oceanodroma leucorhoa. (D) is incorrect because neither the passage nor the graph measures how far away seabirds (DMS-responsive or not) are from DMS before they can detect it, and do not make any claims about this topic.

22. (A) — Reagan explains in the first paragraph that he is about to sit down and sign a bill that will change tax policies that will benefit the American economy, individuals, and families. He then discusses how the recent tax policies have been oppressive and complex. (B) is incorrect because although American families are praised, the main focus of the passage is the tax policies and how they are changing. (C) is incorrect because the passage does not discuss a specific tax code but “a sweeping overhaul of tax code,” and criticizes the current tax system in general, but doesn’t question its benefits (or the benefits of tax reform). (D) is incorrect because the Founding Fathers are celebrated, not scrutinized, in the passage (for example, see lines 25-27).

23. (A) — Reagan describes the previous tax policy as “tangled and complex,” (line 32) “an impossible frustration” for most people (line 34), and as having “undermined livelihoods and constrained [...] freedoms” (lines 64-66). He also compares the current tax code to the “oppressive taxation” that our Founding Fathers fought against (lines 66-67). “Repressive,” which means to hold back or prevent freedom, is the only answer option that is negative enough to capture Reagan’s meaning (B) is incorrect because “constructive” means serving a useful purpose, which doesn’t fit Reagan’s negative characterization of the previous tax policy. (C) is incorrect because “inspiring” carries a positive connotation and means to create a positive feeling in a person. (D) is incorrect because “trivial” means of little value or importance, whereas Reagan suggested that this tax policy did have important, albeit negative, effects.

24. (C) — These lines discuss the “oppressive” and “repressive” nature of taxation as “families saw taxes cut deeper and deeper into their paychecks; taxation fell most cruelly on the poor.” These lines provide the best evidence for the cruel and “repressive” nature of taxation in the previous question. (A) is incorrect because these lines discuss the benefits of Reagan’s plan to change taxation, not the “repressive” nature of the previous tax policy. (B) is incorrect because these lines discuss the Founding Fathers and Bill of Rights and do not mention taxation at all. (D) is incorrect because these lines discuss the promise of hope and opportunity in America and not the “repressive” nature of taxation.

25. (C) — In lines 55-57, Reagan underscores that historically, “the special effort and hard work” of the individual “has always been the driving force of our economy” which aligns with choice (C). (A) is incorrect because Reagan never implies that individuals are only interested in doing work that will benefit themselves. He argues the opposite: that empowered individuals work hard to benefit America’s economy. (B) is incorrect because individual contributions and the contributions of families are never compared. (D) is incorrect because Reagan does not contrast individual values with the American Dream; in fact, he says in line 19 that America was founded on individualistic values.

26. (B) — These lines state that the “individual [...]has always been the driving force of our economy,” which supports- answer choice (A) in the previous question. (A) is incorrect because these lines discuss plans for the growth of the American economy and do not refer to“the individual” in American society. (C) is incorrect because although the lines discuss the individual, they do not address the large contributions “individuals” have made to the American economy. (D) is incorrect because the lines focus on the American dream, and do not discuss the “individual.”

27. (A) — “Tapped a wellspring” in this context means that the Founding Fathers have found a continual and abundant source of “hope and creativity” (line 26) in the American people. This most clearly aligns with answer (A) and the great amount of potential in American individuals. (B) is incorrect because “tapped a wellspring” is being used figuratively in this context; Reagan is not alluding to actual natural resources. (C) is incorrect because although Reagan does reference the creativity of American individuals, he is not comparing America with other countries in this sentence. (D) is incorrect because the “wellspring” refers to the great potential and creativity of American individuals; Reagan is not encouraging or asking American citizens to consider their societal contributions in this part of the passage.

28. (D) — By stating that the Founding Fathers “never imagined” a tax system like the one in place during the writing of Reagan’s speech (lines 28-31), and by contrasting the struggle of “our Founding Fathers” with the results of “oppressive taxation,” Reagan illustrates how far the current tax code has strayed from the original values of the country set forth by Founding Fathers. (A) is incorrect because Reagan never encourages his listeners to learn more about American history in this passage. (B) is incorrect because the passage does not discuss American elections. (C) is incorrect because it is irrelevant: families are discussed in the sixth paragraph, but there is no mention of families exploiting taxes or a connection to the Founding Fathers.

29. (C) — “Tangled” most nearly means “convoluted” or extremely complex and difficult to follow in the context of this sentence. The passage underscores that the tax code has grown increasingly “complex.” (A) “disheveled” is incorrect because it means untidy or disorganized in reference to a person’s hair, clothes, or appearance. This word would not fit in this context to describe the tax code. (B) “knotted” and (D) “matted” are incorrect because they are synonyms that mean to make (something, especially hair) snarled. These words would not fit in this context to describe the tax code.

30. (D) — Reagan repeatedly emphasizes that economic liberties of the American people have been “abused” and “neglected,” or “ignored” in contrast to civil liberties, which have “expanded and strengthened,” according to lines 39-42. (A) is incorrect because economic liberties have been “neglected,” not “broadened.” (B) is incorrect because to “examine” economic liberties would be the opposite of the “neglect” Reagan mentions. (C) is incorrect because Reagan states that economic liberties have been ignored or misused, but he does not suggest that anyone is debating or discussing the value of economic liberties.

31. (B) — In the context of this sentence, “bear” most nearly means “shoulder” or to take on a burden or responsibility. (A) “champion” is incorrect because it means to support or defend a cause. (C) “heft” and (D) “nudge” are incorrect because both imply a physicality that doesn’t fit in the context of the sentence. “Heft” means to lift or carry and “nudge” means a light touch or push, but the passage is implying that families with children have had to deal with increasing amounts of taxes, which do not have any physical weight.

32. (A) — The passage begins with the author referencing research at the University of Wisconsin on whether single-sex schooling “leads to better academic achievement” (line 10), and ends with how gender segregation can affect which profession an individual will pursue; option (A) summarizes both these topics and presents them in the order they appear in the passage, making it the correct answer. Options (B) and (C) are incorrect because the points they present only appear in the middle of the passage, so to say the focus shifted between the two topics they each present would not cover the entire passage, which this question explicitly asks for. (D) is incorrect because the passage only mentions girls’ academic abilities in a single sentence, and never actually discusses the topic, making the topic too fleeting to be considered a focus.

33. (D) — A large portion of this passage deals with how single-sex schools (an example of a segregated environment) foster stereotypes, which matches the claim this option makes. (A) cannot be correct because the passage never compares people who do and do not know they are segregated, or which of these two groups develop stereotypes. (B) is not correct because although the passage does state that stereotypes are an undesirable effect of segregation, it also mentions other downsides to being segregated, such as girls and boys losing opportunities to learn from one another (lines 37-39), and women feeling inhibited from pursuing STEM careers (lines 70-73). (C) is incorrect because the passage states that educational segregation exists because of the belief that boys and girls learn differently, not for the express purpose of causing children to develop stereotypes.

34. (A) — (A) explicitly states that segregation “increases discrimination and stereotyping” (line 53), which matches the correct answer to the previous question. (B) is incorrect because this quote only discusses women in STEM careers, and does not mention stereotypes at all. (C) is incorrect because this option states what factors do not negatively contribute to less women in STEM careers, and does not touch on stereotypes in segregated environments. (D) cannot be correct because claiming men are inhibited from entering professions like nursing and teaching does not independently suggest that stereotypes are more present in segregated environments, which the correct answer to the previous question claims.

35. (C) — As foreshadowed in the previous paragraph, where the author says that “research does not support” the belief that gender segregation provides a tailored learning experience, the author states that there is not much evidence to back up the claim that single-sex education leads to better academic achievement. This idea matches “little”’s meaning of being a small amount, making (C) the correct option. (A) is incorrect because if the evidence was “subtle”, its meaning would be hard to decipher because of its understated nature, but this would not indicate that there is a small amount of it, as this passage is stating. (B) is incorrect because to characterize evidence as “stingy” would mean the evidence was reluctant to share its findings, which is not possible; evidence doesn’t have feelings. The reference is not implying that the evidence is damaged in any way, making “impaired” (D) an incorrect replacement for “scant”.

36. (A) — The author states that there has been evidence against educational segregation since this court case, which (because this court case happened a long time ago, in 1954) implies that this evidence has been around for a long time, giving it the ‘long history’ this option states. (B) cannot be correct because this passage only shows that the Supreme Court has dealt with a case about segregation in schools, not that they are particularly interested in them. Option (C) is incorrect because although this case dealt with racial segregation, the passage makes no claim that there is any difference in severity between racial and gender segregation. Option (D) is incorrect because the author never claims to know where all stereotypes begin (or even attempts to investigate this theory), she only mentions that some exist.

37. (D) — To “cultivate” something means to help something grow; in this context, that something is stereotypes, and the environments where people are separated help stereotypes grow. The passage uses “breeds” to describe this action, but both situations are almost identical, making (D) correct. (A) is not correct because the word “selects” means to choose something, whereas “breeds” in this context is used to describe how stereotypes are transmitted between school children, who are merely following stereotypes, not consciously choosing them. (B) cannot be correct because “instructs” in this passage would imply that stereotypes are being taught, whereas this portion of the passage is describing stereotypes being spread, or “bred”. (C) is incorrect because the term “multiplies” in the context of this sentence could imply that there are more and more different kinds of stereotypes being created, but the passage is only referring to how stereotypes are fostered.

38. (D) — The passage states that the Arizona State University found that children who were separated by their gender eventually developed strong beliefs like “boys are better in math and girls are better in language arts” (lines 57-58). (A) is incorrect because the passage never mentions girls’ preferences for math or any other topic, nor does it claim that the Arizona State University finds that girls perform better in language arts and music. (B) cannot be correct because the passage does not contain information about the gender of teachers, or whether they reinforce stereotypes. (C) is incorrect because research at University of Texas and Penn State University found that children develop favoritism towards members of groups they are placed in, not the University of Arizona.

39. (B) — The author fills this passage with evidence of negative effects of gender segregation, such as the findings of the University of Michigan and Arizona State University’s research. This, coupled with the author’s decision to end this passage by pointing to segregation as the reason people avoid certain careers they might otherwise pursue, reveals the author’s judgemental and negative views towards gender segregation. (A) is incorrect because the author never states that she thinks gender segregation has a positive future, and argues that it causes problems, which does not suggest she has a favorable attitude about the future of gender segregation, given its past and current bad effects. (C) is incorrect because the author never asks questions about what gender segregation is, or expresses any interest in learning more about this topic. (D) is incorrect because although the author is against gender segregation, she never expresses fear towards it, or includes any evidence that suggests fear is an existing attitude towards gender segregation.

40. (B) — This quotation references evidence that single-sex schooling could be harmful to children because of the negative effects it has on children's development later in life, which conveys a critical view of gender segregation, matching the correct answer to the previous question. (A) is incorrect because this quote only states that parents believe boys and girls learn differently, and doesn’t address the author’s opinion or attitude. (C) is incorrect because stating that there is evidence to support the benefits of integration does not show a critical attitude towards segregation. (D) is incorrect because this quote only discusses the interests of girls with and without brothers, not the author’s attitudes.

41. (C) — Information from the passage and the graph shows a significantly less amount of sexist incidents occurring in coeducational schools than single-sex schools, which this option claims. (A) is incorrect because neither the passage or the graph give information about the effects that different types of sexism have on students. (B) is incorrect because even though the graph gives information about the types of sexism that occur in different types of schools, the passage does not claim to know which sexist behaviors children will exhibit based solely on what type of school they attend. (D) is incorrect because the passage does not mention the acceptance of sexism by teachers, and neither does the graph.

42. (B) — The bar that represents all-boys’ schools is higher in the sex-role stereotyping category than in the active discrimination category. (A) is incorrect because the graph shows that there are more sexist incidents overall in all-girls’ schools than all boys’ schools, not the opposite, as this option states. (C) is not correct because the graph shows far more incidents of sex-role stereotyping in all-boys’ schools than coeducational schools, but this option claims there is more sex-role stereotyping in coeducational schools. (D) is incorrect because the combined value of the bars representing all-boys’ schools is far higher than the bar only for gender reinforcement in all-girls’ schools, which this option inverts.

43. (B) — Lines 14-18 discuss the “prohibitive” cost of transporting materials from Earth, implying that this is why scientists would need to develop technology using “material only found on the moon’s surface.” (A) is incorrect because although the passage says that “new machinery may have to be invented,” this is in reference to mining on the moon in general; the passage does not say specifically that it impossible to make concrete on the moon. (C) is incorrect because although lines 52-57 discuss an environmental impact, it is mining that creates this impact, not concrete. (D) is incorrect because although lines 39-45 mention landing pads, only their potential benefits are discussed, not any weaknesses.

44. (B) — These lines indicate that the cost of transporting materials from Earth would be “prohibitive” and that this is why materials on the moon should be used, leading to the conclusion that using lunar materials must be less costly. (A) is incorrect because although new machinery may need to be developed for the moon, concrete is not “machinery”, therefore this information does not apply. (C) is incorrect because these lines only mention the possibility of making landing pads but do not connect them to concrete or a reason to use lunar dust. (D) is incorrect because it discusses the potential environmental impact of mining, not making concrete.

45. (C) — This sentence implies that the scientists might find ways to create waterless concrete out of lunar dust, something which is not currently possible. So, these methods would be “invented” by the scientists. (A) “expand” is incorrect because the passage implies that there are currently no methods for creating waterless lunar concrete, so there is nothing to expand upon. (B) “emerge” is incorrect because it is an intransitive verb; that is, scientists can not “emerge” ways to make concrete, nor can anyone “emerge” a way to do anything; the ‘ways’ must emerge on their own. (D) “spread” is like (A) in that there is no method that currently exists, so there is nothing to spread.

46. (A) — Paragraphs 1-3 discuss the specific conditions under which Earthly technology has developed, and explains why this technology would be impractical for mining the moon — this is the “challenge.” Paragraph 4 then describes pneumatic technology that could overcome the challenges associated with the lunar environment—this is the “solution.” (B) is incorrect because this describes the structure of the final paragraph, but not of the whole passage. (C) is incorrect because although the passage mentions the “past 5,000 years,” the main point of the first few paragraphs is how current technology is impractical for the moon. (D) is incorrect because the passage does not introduce any central scientific concept.

47. (B) — The author’s point is that we are too “caught up in Earthly thinking” to consider how our technology would function on the moon; lines 62-67 give a long list of examples of Earth-specific factors that guided how our technologies had to develop, but which are different on the Moon. (A) is incorrect because the list is not experimental data, and the author does not explain any of the factors in further detail later. (C) is incorrect because the author doesn’t make any claim about how developed our technology is; he just emphasizes that it’s not effective on the moon. (D) is incorrect because the moon is not characterized as harsh in the passage, just different from Earth. Further, Passage 2 does not describe the conditions on Earth as forgiving.

48. (A) — Lines 82-84 say that the “key feature” that eliminates trucks from being viable on the moon is their dependence on dust-producing wheels. (B) is incorrect because the cost of operating trucks on the moon isn’t specifically mentioned, and certainly isn’t described as a “main” problem with using trucks for lunar mining. (C) and (D) are incorrect because although they are both mentioned as factors that would make trucks impractical for the moon, neither is said to be the main factor.

49. (D) — These lines indicate that the “key feature,” or most important factor, that eliminates trucks from being viable on the moon is their dependence of dust producing wheels, which is the correct answer. (A) is incorrect because these lines are too vague; they do not mention trucks or any of their specific negative features. (B) and (C) are incorrect for the same reason that (C) and (D) of the previous question are incorrect: although they both mention reasons that trucks would be impractical for lunar mining, neither is noted to be the most important reason.

50. (B) — The word “condition” is meant to describe the unique parameters of the moon as described in the first paragraph, including its atmospheric and terrestrial conditions, which makes “environment” the correct choice. Answer choice (A) “order” might imply an organization of the moon, which doesn’t make sense in context. (C) “position” describes something’s physical location or its relation to another thing, making it incorrect in context. (D) “habitat” is used to describe the home environment of a living thing, but there is no mention of any creature living on the moon, so (D) is incorrect.

51. (D) — he second paragraph in Passage 2 discusses the issues associated with using trucks in low gravity, whereas Passage 1 mentions no such challenges. (A) is incorrect because both passages consider the possible hazards of moon dust: Passage 1 discusses the “dangerous sandblaster effect” of lunar soil in lines 39-45, and Passage 2 discusses in lines 84-87 how lunar dust can be “pesky and potentially hazardous.” (B) is also incorrect because it is true of both passages: Passage 1 is about a new lunar soil simulant, and Passage 2 proposes a pneumatic mining system. (C) is incorrect because Passage 1 proposes using lunar dust to create concrete, and Passage 2 proposes using lunar silicates to construct the glass tubes for the pneumatic mining system.

52. (C) — Both passages discuss the many challenges currently facing lunar mining, but imply that it is a possibility in the future based on current scientific advancements. Additionally, Passage 1 states in lines 12-13 that “new machinery may have to be invented,” and Passage 2 states in lines 99-100 that there is “much work still to be done” to achieve lunar mining. (A) is incorrect because only Passage 1 discusses the value of lunar minerals, and it states that the value is potentially large. (B) is incorrect because neither passage compares the profits of lunar mining to the profits of mining on Earth. (D) is incorrect because although both passages discuss the potential hazards associated with lunar dust, neither implies that it’s the greatest obstacle to lunar mining.