Below are answer explanations to the full-length English test of the 4th released practice ACT for the Digital ACT.

Other answer explanations in this series of articles:

When you’re finished reviewing this official practice ACT test, start practicing with our own 12 full-length practice ACT tests.

Digital ACT Practice Test 4 English Answer Explanations

Passage 1 – “Missouri’s Elephants”

Question 1, “Which choice most clearly suggests that the boulders appear to be haphazard?” The correct answer is B: “scattered.”

This question tests precision of word choice. The word “scattered” suggests that the boulders are distributed randomly or irregularly, making Choice B the best answer for conveying their haphazard arrangement. Choice A (“spread”) describes the boulders’ distribution but does not necessarily suggest randomness. Choice C (“sitting”) simply describes their stationary position without indicating how they are arranged. Choice D (“placed”) suggests deliberate positioning, which contradicts the writer’s goal of emphasizing their irregular arrangement. Only Choice B clearly communicates that the boulders appear to be randomly distributed.

Question 2, “Which choice makes the sentence most grammatically acceptable?” The correct answer is H: “Some, like.”

This question tests punctuation around an introductory example. The phrase identifying the enormous boulder named “Dumbo” provides an example of rocks that were even larger than elephants. Choice H correctly uses a comma after “Some” to introduce this example, which is then closed by the comma following “Dumbo.” Choice F incorrectly places a comma after “like,” separating the introductory word from the example it introduces. Choice G introduces an em dash without providing a matching closing dash. Choice J omits the comma needed to set off the example. Choice H produces the clearest and most grammatically acceptable construction.

Question 3, “The writer is considering deleting the underlined portion (adjusting the punctuation as needed). Should the underlined portion be kept or deleted?” The correct answer is A: “Kept, because it helps explain why Marina is knowledgeable about the park.”

This question tests the relevance of supporting details. The underlined phrase explains that Marina studied the rocks during her graduate program, establishing why she knows so much about the park’s geology. This information helps readers understand her role in explaining the formation of the boulders, making Choice A correct. Choice B is incorrect because the phrase does not establish Marina’s age relative to the narrator. Choice C mistakenly suggests that information about a secondary character should be removed regardless of its relevance. Choice D focuses on Marina’s motivation for studying rocks, which is not necessary to understanding her expertise.

Question 4, “Which choice best avoids wordiness and redundancy in context?” The correct answer is J: “covered.”

This question tests conciseness and redundancy. The original sentence states that volcanic calderas “covered a section of Missouri in what is now southeastern Missouri,” unnecessarily repeating the geographical information. Choice J eliminates the repetitive wording while preserving the essential statement that the calderas covered southeastern Missouri. Choice F retains the redundancy, while Choice G (“at one time covered the area of”) adds unnecessary words to express the same idea. Choice H (“once covered over”) is also redundant because “once” repeats the historical context already established by “About 1.5 billion years ago,” and “covered over” is less concise than “covered.” Choice J is the most efficient option.

Question 5, “Which choice makes the sentence most grammatically acceptable?” The correct answer is D: “Shards.”

This question tests sentence fragments and dependent clauses. The original sentence begins with “When,” which makes the clause describing the falling shards dependent. Because no independent clause follows, the sentence is incomplete. Choice D removes “When,” allowing “Shards of surface rock and volcanic ash tumbled into the newly exposed chambers” to function as a complete independent clause. Choice A retains the fragment. Choice B (“Then, as shards”) and Choice C (“Because shards”) also introduce dependent clauses without providing a complete independent clause. Only Choice D creates a grammatically complete sentence.

Question 6, “Which choice makes the sentence most grammatically acceptable?” The correct answer is H: “passed, the overlying layer of rock.”

This question tests correct word usage and verb tense. The sentence describes how the overlying rock gradually eroded over time, revealing the granite beneath it. Choice H correctly uses “passed” as the past tense of the verb “pass” and the simple past tense “eroded” to describe this completed geological process. Choice F incorrectly uses “past” instead of “passed” and the ungrammatical expression “would of.” Choice G corrects “would of” to “would have” but retains the incorrect “past.” Choice J also uses “past” incorrectly. Choice H provides the proper verb form and maintains a clear sequence of past events.

Question 7, “Which choice makes the sentence most grammatically acceptable?” The correct answer is B: “them.”

This question tests pronoun-antecedent agreement. The pronoun refers to the granite blocks whose jagged edges were rounded and polished by wind and water. Because “blocks” is plural, the corresponding object pronoun must also be plural. Choice B (“them”) correctly refers to these blocks. Choice A (“this”), Choice C (“that”), and Choice D (“it”) are all singular pronouns, making them inappropriate for referring to the multiple granite blocks described in the sentence. Choice B maintains grammatical agreement and clearly identifies what wind and water polished.

Question 8, “At this point, the writer is considering adding a transition. Which transition word or phrase, if added here, would be most effective in terms of logic and cohesion?” The correct answer is J: “hence,”.

This question tests logical transitions. The passage explains that the continuing cycle of uplift and erosion will eventually expose additional granite blocks, resulting in another generation of the elephant-like boulders. Choice J (“hence”) correctly establishes this cause-and-effect relationship. Choice F (“in spite of this”) and Choice G (“nevertheless”) introduce contrasts that do not exist between the two ideas. Choice H (“for instance”) suggests that the second phrase provides an example rather than a result. Choice J most accurately connects the geological process with its eventual outcome.

Question 9, “Which choice makes the sentence most grammatically acceptable?” The correct answer is A: “No Change.”

This question tests possessive nouns and the correct use of plural forms. The original phrase “the crevices in the rock” correctly describes the cracks that Marina uses while climbing. No possessive construction is necessary because the prepositional phrase “in the rock” already establishes where the crevices are located. Choice B incorrectly adds an apostrophe to the plural noun “crevices.” Choice C introduces unnecessary and incorrect possessive forms in both “rock’s” and “crevices’.” Choice D omits the punctuation or preposition needed to establish a relationship between “rocks” and “crevices.” Choice A is already grammatically correct.

Question 10, “Which choice most effectively concludes the essay by referencing what the narrator learned about Elephant Rocks State Park?” The correct answer is J: “future elephants lying hidden beneath my feet.”

This question tests effective conclusions and connections to an essay’s central ideas. Throughout the passage, Marina explains how geological forces created the enormous granite boulders and how erosion will eventually expose additional rocks. Choice J references this lesson by suggesting that future elephant-like boulders remain hidden beneath the ground. Choice F focuses on the narrator’s relationship with Marina rather than what was learned about the park. Choice G emphasizes the surrounding visitors and scenery, while Choice H describes the narrator’s physical discomfort and curiosity without connecting to the specific geological explanation. Choice J provides the strongest thematic conclusion.

Passage 2 – “The Surprising Allure of Slow TV”

Question 11, “Which choice makes the sentence most grammatically acceptable?” The correct answer is C: “launched a new national pastime:”

This question tests punctuation when introducing an explanation or identification. Choice C correctly uses a colon after the complete statement that NRK launched a new national pastime, introducing “slow TV” as the name of that pastime. Choice A incorrectly places a colon immediately after the verb “launched,” separating the verb from its object. Choice B introduces an unnecessary comma after “launched” and uses an em dash in a way that disrupts the sentence’s construction. Choice D omits the punctuation necessary to separate the general description from the specific term “slow TV.” Choice C clearly and grammatically introduces the new concept.

Question 12, “Which choice makes the sentence most grammatically acceptable?” The correct answer is J: “were.”

This question tests subject–verb agreement. The subject of the sentence is “Both the station and social media,” which joins two nouns using “and.” Because this is a compound subject, it requires a plural verb. Choice J (“were”) correctly agrees with the subject. Choice F (“was”) uses a singular verb, while Choice G (“was being”) and Choice H (“was soon”) retain the same subject–verb disagreement. The correct sentence states that both the broadcasting station and social media were flooded with suggestions for future programs. Choice J maintains the required plural agreement.

Question 13, “Which choice most effectively creates a connection between the preceding paragraph and this paragraph?” The correct answer is B: “That excitement inspired one of NRK’s most ambitious projects—”.

This question tests transitions between paragraphs. The preceding paragraph describes the unexpectedly enthusiastic public response to NRK’s first slow TV program, including suggestions for future projects. Choice B connects that excitement directly to the broadcaster’s decision to undertake a much more ambitious production. Choice A introduces the new project without explaining how it relates to the audience’s earlier response. Choice C provides information about the project and its date but does not establish a meaningful connection. Choice D identifies the Hurtigruten project without linking it to the preceding paragraph. Choice B most effectively establishes continuity between the ideas.

Question 14, “Which choice best maintains the stylistic pattern established in the sentence?” The correct answer is J: “some stood alone on rocky outcroppings;”.

This question tests parallel structure. The sentence describes several ways Norwegians responded to the Hurtigruten broadcast using a repeated pattern: “Some crowded,” “some stood,” and “others … sailed.” Choice J preserves this pattern by using the same straightforward subject–verb construction. Choice F introduces a passive phrase, “some were seen standing,” which interrupts the parallel structure. Choice G adds the unnecessary word “people,” making the second item less concise than the others. Choice H changes the natural word order and interrupts the sentence with unnecessary commas. Choice J provides the most consistent and effective parallel construction.

Question 15, “Which choice best avoids wordiness and redundancy in context?” The correct answer is A: “No Change.”

This question tests concise and precise language. The original phrase “an all-time high for NRK” clearly communicates that the broadcast achieved the largest audience in the station’s history. Choice A expresses this achievement without unnecessary repetition. Choice B (“unsurpassed, record-breaking success and achievement”) combines multiple phrases with overlapping meanings. Choice C (“exceptional, incomparable, and rare triumph”) similarly piles together adjectives that express nearly the same idea. Choice D (“unusual and unprecedented event”) is less precise and repeats the idea of something being extraordinary. The original phrasing is the clearest and most concise.

Passage 3 – “Goode’s Idea”

Question 16, “At this point, the writer is considering adding the following sentence to the beginning of the essay: ‘Many people find furniture useful.’ Should the writer make this addition here?” The correct answer is H: “No, because the sentence is an overgeneralization that is not specifically tied to the main subject of the first paragraph.”

This question tests the relevance of introductory information. The proposed sentence makes a broad, obvious observation about furniture but does not introduce Sarah Goode, her invention, or the historical significance of her folding cabinet bed. Choice H correctly identifies why the sentence would weaken the introduction. Choice F is incorrect because the sentence does not explain Goode’s decision to live in Chicago or open a furniture store. Choice G is unsupported because the sentence provides no information about nineteenth-century furniture preferences. Choice J identifies a possible weakness but is less accurate because the existing paragraph already establishes the historical context. The primary problem is the sentence’s lack of relevance and specificity.

Question 17, “Which choice makes the sentence most grammatically acceptable?” The correct answer is D: “who.”

This question tests relative pronouns and their grammatical functions. The pronoun refers to “people” and serves as the subject of the verb “needed” in the clause describing customers who required space-saving furniture. Choice D (“who”) is therefore correct. Choice A (“whom needed”) incorrectly uses an object pronoun as the subject of a verb. Choice B (“which”) is generally used for things rather than people in this context. Choice C (“whom”) repeats the same incorrect object-pronoun usage found in the original sentence. Choice D correctly identifies the people performing the action in the relative clause.

Question 18, “Which choice makes the sentence most grammatically acceptable?” The correct answer is G: “which.”

This question tests sentence structure and comma splices. The original sentence joins two independent clauses with only a comma: one identifies the base of the cabinet bed, and the other explains how its width determined the bed’s dimensions. Choice G replaces the beginning of the second clause with “which,” turning it into a dependent relative clause that modifies “base.” Choice F retains the comma splice. Choices H (“this”) and J (“it”) both create independent clauses that would still be improperly joined to the first clause by a comma. Choice G produces a complete, grammatically correct sentence while clearly establishing the relationship between the base and the unfolded bed.

Question 19, “Which choice makes the sentence most grammatically acceptable?” The correct answer is A: “No Change.”

This question tests punctuation around descriptive phrases. The original wording “a mattress folded into thirds” correctly integrates the phrase “folded into thirds” into the noun phrase describing the mattress. No comma is necessary between “mattress” and its identifying description. Choice B incorrectly separates “folded” from “into thirds” with a comma. Choice C inserts an unnecessary comma after “mattress,” disrupting the natural construction of the sentence. Choice D incorrectly places a comma after “folded,” separating the verb form from the phrase that completes its meaning. Choice A maintains the clearest and most grammatically acceptable description.

Question 20, “Which transition word or phrase is most logical in context?” The correct answer is J: “Thus,”.

This question tests cause-and-effect transitions. The passage explains that Goode’s desk surface could be lifted until it stood upright, perpendicular to the floor. As a result, that surface could serve as the bed’s headboard. Choice J (“Thus”) correctly establishes this consequence. Choice F (“For example”) suggests that the headboard function is merely an illustration rather than a direct result of the preceding action. Choice G (“Similarly”) introduces a comparison that does not exist. Choice H (“Moreover”) suggests an additional, loosely connected fact rather than the result of the transformation. Choice J most accurately conveys the logical relationship.

Question 21, “Which choice makes the sentence most grammatically acceptable?” The correct answer is A: “No Change.”

This question tests sentence completeness and verb structure. The original phrase “the now-vertical writing surface could serve as the bed’s headboard” contains a clear subject and the verb phrase “could serve,” making it a complete independent clause. Choice A is therefore grammatically correct. Choice B (“which served”) introduces a relative clause that cannot stand independently in this construction. Choice C (“serving”) changes the main verb into a participle and creates a fragment. Choice D removes the underlined verb phrase entirely, leaving the sentence without the necessary predicate. Choice A maintains the complete sentence structure.

Question 22, “Which choice is least redundant in context?” The correct answer is J: “conversion.”

This question tests conciseness and redundancy. The passage has already described the steps necessary to transform Goode’s desk into a bed, so the phrase “conversion from desk to bed” unnecessarily repeats information. Choice J removes the redundant description, producing the concise statement that the bed conversion was complete. Choice F retains the repetition. Choice G (“conversion, made possible by Goode,”) adds an unnecessary reminder of the inventor’s involvement. Choice H (“conversion, simplified by Goode,”) similarly repeats a point already established by the description of her innovative design. Choice J communicates the conclusion most efficiently.

Question 23, “Given that all the following choices are accurate, which one most effectively introduces this paragraph by echoing a point made about the cabinet bed in the first paragraph of the essay?” The correct answer is A: “No Change.”

This question tests paragraph cohesion and thematic connections. The original phrase “Born of necessity” echoes the introduction’s explanation that Goode designed her cabinet bed to meet the needs of city residents living in small apartments. Choice A therefore connects the invention’s practical purpose with its popularity among nineteenth-century customers. Choice B introduces broad economic circumstances rather than the specific need for space-saving furniture. Choice C shifts the focus to the lack of information about Goode’s life, which does not connect to the paragraph’s discussion of commercial success. Choice D returns to the mechanics of converting the bed rather than explaining why customers valued it.

Question 24, “Which choice most effectively maintains the essay’s tone?” The correct answer is J: “Even over one hundred years later,”.

This question tests tone and formality. The passage uses an informative, professional style to describe Goode’s invention and its continuing influence on furniture design. Choice J maintains that style while emphasizing the remarkable duration of her contribution. Choice F (“Random, I know, but”) introduces an overly casual aside that does not fit the essay. Choice G includes the conversational parenthetical “which is kind of a long time,” while Choice H (“Hard to believe that”) unnecessarily inserts the writer’s personal reaction. Choice J provides a clear, polished transition consistent with the passage’s tone.

Question 25, “Suppose the writer’s primary purpose had been to describe furniture making in the late nineteenth century. Would this essay accomplish that purpose?” The correct answer is C: “No, because it instead focuses on one specific piece of furniture that Goode designed and the functionality of that piece.”

This question tests identification of an essay’s primary purpose. Although the passage discusses an invention from the late nineteenth century, its central focus is Sarah Goode’s folding cabinet bed, including its design, transformation process, and usefulness to customers. Choice C correctly recognizes that the essay does not provide a broad account of furniture making during the period. Choice A incorrectly suggests that the essay compares Goode’s techniques with those of other designers. Choice B claims that Goode’s designs represent widely available furniture, which is not established. Choice D incorrectly identifies furniture advertising as the essay’s focus, even though the passage does not discuss advertising methods.

Passage 4 – “Drumming Up a World of Sound”

Question 26, “Which transition word or phrase is most logical in context?” The correct answer is J: “There,”.

This question tests transitions and references to locations. The passage first establishes that Evelyn Glennie attended London’s Royal Academy of Music, then describes the advice she received from professors at that institution. Choice J (“There”) correctly refers back to the academy and identifies where the conversation occurred. Choice F (“In retrospect”) suggests that the professors’ warning is being reconsidered from a later perspective rather than identifying its location. Choice G (“On the other hand”) introduces a contrast that does not exist. Choice H (“Furthermore”) suggests an additional point without clearly connecting the professors’ advice to the academy. Choice J provides the most logical and cohesive transition.

Question 27, “If the writer were to delete the underlined portion (adjusting the punctuation as necessary), the essay would primarily lose a detail:” The correct answer is C: “indicating that Glennie’s professors did not anticipate her success.”

This question tests the rhetorical function of supporting details. The underlined phrase explains that Glennie’s professors believed a person could not succeed as a full-time solo percussionist. This establishes their skepticism and creates a contrast with Glennie’s eventual achievements, making Choice C correct. Choice A incorrectly suggests that the detail establishes Glennie as the first successful solo percussionist, which the passage does not explicitly claim. Choice B focuses on Glennie’s own doubts rather than her professors’ expectations. Choice D incorrectly suggests that the professors encouraged her to study multiple instruments, which is not discussed. The detail primarily emphasizes how unexpected her success appeared to her teachers.

Question 28, “Which choice most effectively maintains the essay’s tone?” The correct answer is F: “No Change.”

This question tests appropriate tone and word choice. The original phrase “captivating audiences with her innovative musicianship” conveys Glennie’s success in a polished, professional manner consistent with the rest of the essay. Choice F therefore maintains the appropriate tone. Choice G uses the awkward and redundant expression “innovational and originative ways” alongside the informal phrase “make a hit.” Choice H (“roping in her audiences”) is overly conversational. Choice J (“very much wowing audiences”) is similarly informal and less precise than the original wording. Choice F communicates Glennie’s accomplishments clearly without unnecessary exaggeration or awkward phrasing.

Question 29, “Which choice is least redundant in context?” The correct answer is D: “and detect certain pitches.”

This question tests conciseness and the elimination of redundant language. The passage has already established that Glennie performs barefoot and uses her feet to sense musical vibrations. Choice D preserves the important information that this ability also helps her detect certain pitches without repeating how she uses her feet. Choice F redundantly describes using her feet to perceive vibrations after already explaining that she feels them. Choice B repeats the same idea with the phrase “by way of her feet.” Choice C unnecessarily restates that her feet are bare. Choice D expresses the additional information most efficiently.

Question 30, “Which choice makes the sentence most grammatically acceptable?” The correct answer is G: “as.”

This question tests comparative constructions and parallel structure. The sentence compares the intensity with which Glennie listens to everyday street sounds and orchestral music. Standard English uses the construction “as … as” to establish this kind of equality, so Choice G produces “as intensely … as she does.” Choice F (“quite”) does not complete the required comparative structure. Choice H (“so”) creates an awkward and grammatically inappropriate comparison. Choice J removes the first comparative word entirely, leaving the sentence without the necessary parallel construction. Choice G correctly establishes that Glennie listens to both kinds of sound with equal intensity.

Passage 5 – “Nature’s Bug Spray”

Question 31, “Which choice makes the sentence most grammatically acceptable?” The correct answer is D: “is.”

This question tests subject–verb agreement. The subject is “the marsh Labrador tea plant,” which is singular despite the intervening descriptive phrase identifying it as a flowering shrub. The sentence therefore requires the singular verb “is,” making Choice D correct. Choice F (“have been”) and Choice B (“have”) both use plural verb forms that do not agree with the singular subject. Choice C (“are”) is also plural. Choice D correctly produces the expression “is esteemed,” describing the plant’s reputation as a natural moth repellent in Scandinavian folklore.

Question 32, “The writer is considering deleting the underlined portion. Should the underlined portion be kept or deleted?” The correct answer is F: “Kept, because it clarifies the specific nuisance caused by moths and why clothing needs protection from them.”

This question tests the relevance of descriptive details. The underlined phrase identifies moths as “wool-gnawing,” explaining the particular damage they can cause to stored clothing and why people would want to repel them. Choice F correctly identifies the purpose of this detail. Choice G incorrectly suggests that the phrase explains why moths avoid marsh Labrador tea, which is addressed elsewhere in the passage. Choice H wrongly characterizes the detail as an unsupported generalization. Choice J focuses on why moths are attracted to wool, but the phrase is included to emphasize the damage they cause rather than explain that attraction. Keeping the phrase helps readers understand the practical need for protection.

Question 33, “Which choice is least redundant in context?” The correct answer is D: “practice.”

This question tests redundancy and conciseness. The preceding sentence already explains that people have historically stored marsh Labrador tea branches with winter clothing to repel moths. Consequently, repeating the full description of this activity is unnecessary. Choice D (“practice”) refers clearly to the previously described tradition while eliminating repetitive information. Choice F repeats the explanation of storing branches with clothing. Choice B adds another unnecessary reminder that the practice is intended to repel moths naturally. Choice C (“commonly used practice”) is redundant when followed by the statement that the practice remains popular today. Choice D is the clearest and most concise option.

Question 34, “Which choice makes it clear that Holopainen was organizing and classifying the various gases emitted from the mountain birch tree?” The correct answer is G: “cataloguing.”

This question tests precision of word choice. The writer wants to communicate that Holopainen was systematically identifying, organizing, and classifying gaseous emissions. Choice G (“cataloguing”) accurately describes this process of recording and classifying information. Choice F (“noting”) suggests observing or recording something but does not necessarily imply systematic organization. Choice H (“counting”) focuses on determining quantities rather than identifying and classifying different compounds. Choice J (“placing”) describes positioning objects and does not fit the scientific activity being discussed. Choice G most precisely conveys the intended research process.

Question 35, “Which choice makes the sentence most grammatically acceptable?” The correct answer is C: “of which.”

This question tests relative pronouns and sentence structure. The sentence explains that the chemical compounds normally come from marsh Labrador tea plants and that several of these plants grew near the birch tree. Choice C (“of which”) correctly introduces a relative clause referring to the previously mentioned plants. Choice A creates a comma splice by joining two independent clauses with only a comma. Choice B (“of the plants”) retains the same problem because it creates another independent clause after the comma. Choice D removes the underlined portion without providing a grammatical connection between the two ideas. Choice C creates a clear and complete sentence.

Question 36, “Which choice makes the sentence most grammatically acceptable?” The correct answer is J: “theorized that.”

This question tests punctuation and the construction of noun clauses. The verb “theorized” introduces the content of Holopainen’s hypothesis through the conjunction “that.” Choice J correctly connects the verb to the following clause without unnecessary punctuation. Choice F incorrectly places a colon immediately after “that,” separating the conjunction from the clause it introduces. Choice G places the colon before “that,” which is also inappropriate because the clause is functioning as the object of the verb. Choice H inserts an unnecessary comma between “theorized” and “that.” Choice J preserves the correct grammatical relationship.

Question 37, “Which choice makes the sentence most grammatically acceptable?” The correct answer is A: “No Change.”

This question tests sentence structure and verb forms. The original sentence uses the complete verb phrase “was engaging” to explain that the birch tree participated in a process called associational resistance. Choice A correctly provides the independent clause with its necessary main verb. Choice B (“which was engaged”) introduces a relative clause that disrupts the sentence and leaves the main clause incomplete. Choice C (“being engaged”) substitutes a participial construction that cannot serve as the sentence’s main verb. Choice D deletes the essential verb phrase, creating a fragment. Choice A maintains a complete and grammatically correct sentence.

Question 38, “Which transition word or phrase is most logical in context?” The correct answer is H: “Moreover,”.

This question tests logical transitions between related ideas. The paragraph explains that the study demonstrated how nearby plant species can depend on one another for survival. It then expands upon this finding by emphasizing the importance of considering plants within an ecological community rather than as isolated individuals. Choice H (“Moreover”) appropriately introduces this additional implication. Choice F (“Still”) and Choice J (“Even so”) suggest a contrast or concession that does not exist. Choice G (“For example”) implies that the following statement provides a specific illustration, when it actually presents a broader conclusion. Choice H most accurately connects the related ideas.

Question 39, “The writer wants to add the following sentence to the essay: ‘Using portable collection chambers, the researchers trapped, and then analyzed, gases released from various plant species.’ The sentence would most logically be placed at:” The correct answer is A: “Point A in Paragraph 2.”

This question tests logical sentence placement. The proposed sentence describes the method the researchers used to collect and analyze gaseous emissions. Point A occurs immediately after the paragraph introduces their purpose of identifying emissions from trees and plants, making it the most appropriate place to explain their procedure. Choice B would place the explanation after the specific compounds found near the birch tree had already been introduced. Choices C and D would place the methodological detail in Paragraph 3, which focuses on Holopainen’s interpretation of the findings rather than the research procedures. Choice A maintains the clearest progression from research purpose to method to discovery.

Question 40, “Suppose the writer’s primary purpose had been to compare methods of survival used by two plant species native to Scandinavia. Would this essay accomplish that purpose?” The correct answer is J: “No, because it focuses instead on the beneficial relationship between two plant species by explaining how they protect themselves from herbivores.”

This question tests identification of an essay’s primary purpose. The passage explains how marsh Labrador tea releases chemicals that repel herbivores and how nearby birch trees can absorb and rerelease those compounds, benefiting from the same protective effect. Rather than systematically comparing two independent survival methods, the essay focuses on the relationship between the plants. Choice J correctly identifies this focus. Choice F incorrectly suggests that the passage lists multiple shared defenses. Choice G introduces genetic similarities and differences in plant height, neither of which is discussed. Choice H places too much emphasis on folklore, which primarily serves as an introduction to the scientific findings.

Passage 6 – “AI-Assisted Judging: A Gold Medal Idea”

Question 41, “Which choice makes the sentence most grammatically acceptable?” The correct answer is B: “enthusiast, I often struggle to distinguish the great performances.”

This question tests punctuation in introductory phrases and verb complements. Choice B correctly places a comma after the introductory phrase “As a casual enthusiast” and avoids inserting an unnecessary comma between “the great performances” and the phrase “from the merely good.” Together, these elements complete the expression “distinguish … from.” Choice A incorrectly separates the two parts of that expression with a comma. Choice C omits the comma after the introductory phrase while retaining an unnecessary comma after “performances.” Choice D removes both commas, including the one needed after “enthusiast.” Choice B maintains the correct punctuation throughout.

Question 42, “The writer wants to emphasize that the nuances of a performance can separate the very best athletes from others. Which choice best accomplishes that goal?” The correct answer is H: “a subtle detail that could separate.”

This question tests precision and rhetorical emphasis. The writer wants to highlight how very small differences in an athlete’s performance can determine whether the athlete receives an excellent score or a perfect one. Choice H uses “a subtle detail” to emphasize the importance of these fine distinctions. Choice F (“an error separating”) focuses on an identifiable mistake rather than the broader idea of a nuance. Choice G (“the impressive elements separating”) suggests conspicuous achievements rather than subtle distinctions. Choice J (“what often separates”) is vague and does not emphasize the small details involved. Choice H most effectively captures the intended meaning.

Question 43, “If the writer were to delete the underlined portion, the essay would primarily lose:” The correct answer is D: “a rationale for the essay’s main argument about Olympic judging.”

This question tests the function of supporting claims within an argument. The underlined phrase explains that the purpose of incorporating artificial intelligence into Olympic judging is to ensure that athletes are evaluated fairly. This provides the reasoning behind the writer’s recommendation, making Choice D correct. Choice A incorrectly characterizes the argument as advocating the replacement of human judges, whereas the essay ultimately supports assisting them with AI. Choice B focuses on historical examples of unfair judging, which the phrase does not provide. Choice C describes a claim about Olympic judging but overlooks the phrase’s more specific function of explaining why the proposed change is necessary.

Question 44, “Which choice makes the sentence most grammatically acceptable?” The correct answer is F: “No Change.”

This question tests modifying phrases and parallel structure. The original sentence explains that training an AI model on footage teaches it to perform three related tasks: identify tricks, distinguish between different landing qualities, and recognize small flaws. Choice F correctly uses “teaching” to describe the effect of the training and maintains parallel verbs throughout the list. Choices G and H incorrectly substitute “learning” for “teaching,” weakening the relationship between the training process and the model’s acquired abilities. Both also introduce unnecessary commas that interrupt the comparison between a good landing and an okay landing. Choice J removes punctuation and makes it appear that the footage itself is learning, rather than the AI model. Choice F is the clearest and most grammatically sound construction.

Question 45, “The writer wants to raise and refute a potential counterpoint related to outsourcing Olympic judging to AI. Which choice best accomplishes that goal?” The correct answer is A: “No Change.”

This question tests the effective introduction and refutation of a counterargument. The original sentence acknowledges the concern that artificial intelligence might eventually replace human judges entirely and immediately rejects that possibility. The following sentences explain that human judgment remains necessary for evaluating subjective qualities such as artistry and style. Choice A therefore establishes a counterargument that the paragraph directly addresses. Choice B presents AI as a helpful tool rather than introducing an objection. Choice C predicts that judges will embrace AI, which is not a counterargument. Choice D questions AI’s overall ability to judge athletes, but the paragraph does not refute that claim as directly as it addresses the concern about replacing human judges.

Question 46, “Which choice makes the sentence most grammatically acceptable?” The correct answer is H: “so.”

This question tests the connection of independent clauses. The first clause explains that subjective qualities such as artistry and style are difficult for AI to evaluate, while the second states that human judges must remain central to the process. Choice H (“so”) correctly joins these independent clauses using a coordinating conjunction that establishes a cause-and-effect relationship. Choice F (“thus”) and Choice G (“therefore”) are conjunctive adverbs, which cannot join independent clauses using only a comma. Choice J removes the connecting word entirely, creating a comma splice. Choice H maintains grammatical correctness while expressing the intended relationship.

Question 47, “Which choice is clearest and most grammatically acceptable in context?” The correct answer is D: “Complementing human judges with AI.”

This question tests commonly confused words and pronoun clarity. The verb “complementing” means adding something that improves or completes another thing, which accurately describes using AI to assist human judges. Choice D also explicitly identifies AI as the technology providing that assistance. Choice A incorrectly uses “complimenting,” which means praising someone, and the vague pronoun “this.” Choice B uses the correct verb but retains the unclear reference to “this.” Choice C names AI but incorrectly uses “complimenting.” Choice D is the only option that combines the correct word with a clear identification of the technology.

Question 48, “Which choice most effectively maintains the essay’s tone?” The correct answer is F: “No Change.”

This question tests tone and precision. The original wording describes AI helping judges review “complex routines and tricks” and resolve athletes’ challenges more fairly. These phrases are specific, professional, and consistent with the essay’s discussion of Olympic judging. Choice G uses informal expressions such as “flashy moves” and “settle things,” which weaken the formal tone. Choice H combines the overly casual phrase “hard-to-judge stuff” with unnecessarily elaborate language about impartial determinations. Choice J uses awkward wording and the incorrect expression “to solution disputes.” Choice F maintains a clear, appropriate, and professional style.

Question 49, “Which choice best concludes the essay by framing the essay’s argument in a way that assumes widespread agreement?” The correct answer is C: “who could be opposed to that?”

This question tests rhetorical conclusions. The writer wants to conclude by presenting AI-assisted judging as such a reasonable improvement that readers will naturally agree with the proposal. Choice C uses a rhetorical question that assumes there is little reason to oppose making Olympic judging fairer. Choice A recommends employing the technology but does not imply widespread agreement. Choice B enthusiastically urges action without suggesting that opposition would be unreasonable. Choice D proposes giving the technology a chance, which is more tentative than the writer’s intended conclusion. Choice C most directly frames the argument as one that should attract broad support.

Question 50, “The writer is considering adding the following accurate sentence to the essay: ‘The X Games even introduced AI to help judge its snowboarding competitions.’ If the writer were to add the sentence, it would most logically be placed at:” The correct answer is J: “Point D in Paragraph 4.”

This question tests logical sentence placement and the organization of supporting evidence. Paragraph 4 discusses existing applications of AI-assisted judging, including its use in tennis and its testing in Major League Baseball. The proposed sentence about the X Games provides another relevant example of AI being incorporated into sports officiating, making Point D the most logical placement. Choice F would interrupt the introduction before the essay establishes its argument. Choice G would place the example in a paragraph focused on explaining how AI judging systems function. Choice H would interrupt the discussion of why human judges remain necessary. Choice J groups the example with similar evidence and strengthens the essay’s concluding argument.

Additional ACT practice test answer explanations