All practice questions

5556 questions

Question 901Question

In 1967, astrophysicist Jocelyn Bell Burnell detected a series of highly regular radio pulses while analyzing data from a newly constructed telescope. These strange signals, which were initially nicknamed 'Little Green Men' turned out to be the first evidence of rotating neutron stars. Today, these stars, known as pulsars, help astronomers map the structure of our galaxy.

Which of the following options represents the correct punctuation for the underlined portion?

Show answer & explanation

Answer: signals, which were initially nicknamed 'Little Green Men,' turned

Answer

The correct option is the one that places a comma both before and after the nonessential relative clause, resulting in: 'signals, which were initially nicknamed 'Little Green Men,' turned'
The clause 'which were initially nicknamed 'Little Green Men'' is a nonessential relative clause because the sentence remains grammatically complete and retains its core meaning without it. Nonessential elements must be set off by a pair of commas. Placing a comma after 'signals' and another after 'Men' correctly encloses the parenthetical information.

Step-by-Step Solution

1
Identify the clause following the noun 'signals'.
The clause 'which were initially nicknamed 'Little Green Men'' is a nonessential relative clause because it provides extra background information and is not necessary to identify which signals are being discussed.
Nonessential elements must be set off from the rest of the sentence with punctuation on both sides.
2
Determine the correct punctuation to enclose the nonessential clause.
Commas are the appropriate punctuation to set off this nonessential clause. A comma must be placed both before the clause (after 'signals') and after the clause (after 'Men').
Omitting either comma or using incorrect punctuation like a semicolon creates grammatical errors.

Key Concept

Commas with Nonessential and Parenthetical Elements
Estimated Time:45s
Question 902Question

Marie Tharp's career in cartography began at a time when women were barred from conducting research aboard vessels. Staying behind at Columbia University, Tharp transformed raw sonar data collected by her colleague Bruce Heezen into detailed three-dimensional drawings of the ocean floor. By meticulously plotting these depth measurements, she discovered a massive V-shaped rift valley running down the center of the Mid-Atlantic Ridge. While Heezen initially dismissed her findings as "girl talk" that supported the then-controversial theory of continental drift, Tharp persisted, eventually convincing him that the valley was real.

The writer wants to add a sentence at the end of the passage to conclude the paragraph by summarizing the significance of Tharp's discovery. Which choice best accomplishes this goal?

Show answer & explanation

Answer: This detailed map provided the visual evidence needed to validate seafloor spreading, which ultimately established the foundation for the modern theory of plate tectonics.

Answer

The choice that explains how Tharp's map provided the visual evidence needed to validate seafloor spreading and establish the foundation for plate tectonics.
The correct option successfully summarizes the significance of Tharp's work (the map) by connecting her discovery of the rift valley directly to the validation of seafloor spreading and plate tectonics, which were the central subjects of the passage. It remains grammatically correct and flows logically from the preceding sentence.

Step-by-Step Solution

1
Identify the primary topic and thesis of the paragraph.
The paragraph focuses on Marie Tharp's mapping work, specifically her discovery of the Mid-Atlantic Ridge's rift valley, and how it supported the controversial theory of continental drift.
An effective concluding sentence must tie directly back to the main thesis of the passage without introducing unsupported or peripheral details.
2
Evaluate the transitions and logical flow of the options.
The option starting with 'In spite of this' incorrectly uses a contrasting transition immediately after Tharp succeeds in convincing her colleague. The option starting with 'Consequently' uses a cause-and-effect transition but leads into an unrelated clause about awards. The option starting with 'This detailed map' logically continues the narrative flow by explaining the impact of the map.
Concluding sentences must transition logically from the preceding sentence.
3
Check the remaining options for grammatical errors and thematic relevance.
The option starting with 'Consequently' is a comma splice, joining two independent clauses with only a comma. The option starting with 'Furthermore' contains an inconsistent present-tense shift ('ensures') and shifts the paragraph's focus to general academic sexism. The option starting with 'This detailed map' is grammatically correct and directly summarizes the scientific significance of her work.
The correct choice must be grammatically correct and keep the focus on the main topic.

Key Concept

Selecting Concluding Sentences
Question 903Question

Although the software developers spent weeks refining the neural network's architecture; the unpredictable, complex, computer program crashed when exposed to the new dataset.

Which choice best punctuates the underlined portion of the sentence?

Show answer & explanation

Answer: architecture, the unpredictable, complex computer program crashed

Answer

architecture, the unpredictable, complex computer program crashed
The correct answer correctly places a comma after the introductory adverbial clause ending with 'architecture'. It also correctly places a single comma between the coordinate adjectives 'unpredictable' and 'complex' while omitting any punctuation between the cumulative modifier 'computer' and the noun 'program', and between the subject 'program' and its verb 'crashed'.

Step-by-Step Solution

1
Analyze the clause structure of the sentence.
The sentence begins with the subordinating conjunction 'Although', introducing a dependent adverbial clause: 'Although the software developers spent weeks refining the neural network's architecture'. This dependent clause must be joined to the subsequent independent clause using a comma, not a semicolon.
Semicolons are only used to connect two independent clauses, whereas a dependent clause must be followed by a comma when it introduces a sentence.
2
Evaluate the adjectives preceding the noun 'program' to determine if they are coordinate or cumulative.
The adjectives are 'unpredictable', 'complex', and 'computer'. 'Unpredictable' and 'complex' are coordinate because they can be reordered ('complex, unpredictable') and joined by 'and' ('unpredictable and complex') while retaining the original meaning. 'Complex' and 'computer' are cumulative because 'computer program' functions as a compound unit, and we cannot say 'complex and computer program'. Therefore, a comma must separate 'unpredictable' and 'complex', but no comma should follow 'complex' or separate 'computer' from 'program'.
Coordinate adjectives require separating commas, whereas cumulative adjectives and noun adjuncts do not.
3
Check the transition between the subject and the verb.
The subject 'program' should directly connect to the verb 'crashed' without any intervening punctuation.
A single comma should never separate a subject from its main verb.

Key Concept

Identifying introductory dependent clauses, distinguishing coordinate from cumulative adjectives, and avoiding incorrect punctuation between subjects and verbs.
Estimated Time:1m 15s
Question 904Question

The following is an essay about a late-nineteenth-century invention:

[1]
In the late nineteenth century, the introduction of the safety bicycle revolutionized personal mobility. Unlike its predecessor, the "ordinary" or "penny-farthing"—which featured a massive front wheel, lacked brakes, and posed a constant threat of header crashes—the safety bicycle boasted two equal-sized wheels, a chain drive, and pneumatic tires. Cycling was no longer a dangerous stunt reserved for athletic young men; it became an accessible, comfortable activity for the general public.

[2]
Perhaps no group was more profoundly affected by this technological shift than women. For decades, societal norms restricted women's independence, confining their travel largely to distances they could walk or journeys chaperoned in carriages. The safety bicycle provided an unprecedented means of self-locomotion. Susan B. Anthony famously remarked that bicycling had "done more to emancipate women than anything else in the world," giving them a feeling of freedom and self-reliance.

[3]
The bicycle also drove significant changes in women's fashion. To ride comfortably, women abandoned heavy, restrictive Victorian corsets and voluminous skirts in favor of "rational dress," which included bloomers and shorter skirts. Although conservative critics decried these changes as scandalous, the practicality of the bicycle triumphed. In this way, the safety bicycle did not merely change how people traveled; it reshaped the social fabric of the era.

Suppose the writer’s goal had been to write an essay that traces the mechanical evolution of the bicycle from its earliest prototypes to modern designs. Would this essay accomplish that goal?

Show answer & explanation

Answer: No, because the essay focuses primarily on the social and cultural effects of the safety bicycle, particularly regarding women’s independence and clothing.

Answer

No, because the essay focuses primarily on the social and cultural effects of the safety bicycle, particularly regarding women’s independence and clothing.
The essay does not accomplish the proposed goal. While the first paragraph touches on the mechanical differences between the penny-farthing and the safety bicycle, the majority of the essay is dedicated to explaining how the safety bicycle impacted women's social independence and fashion choices. Therefore, the correct choice is the option stating that the essay does not accomplish the goal because it focuses primarily on these social and cultural effects.

Step-by-Step Solution

1
Analyze the proposed writing goal in the prompt.
The goal is to trace the mechanical evolution of the bicycle from earliest prototypes to modern designs.
Understanding the goal is necessary to evaluate the essay against it.
2
Analyze the main focus and contents of the provided essay.
The essay discusses the safety bicycle's introduction, its impact on women's independence, and the resulting changes in women's fashion.
Evaluating the actual content of the essay reveals whether the goal was met.
3
Compare the proposed goal with the actual content of the essay.
The essay does not trace mechanical evolution to modern designs; it focuses on social and cultural effects. Thus, the essay does not fulfill the goal.
Making this comparison allows for selecting the correct 'No' option with the accurate explanation.

Key Concept

Evaluating Whole-Essay Goals and Purpose
Estimated Time:1m 30s
Question 905Question

Read the passage below. Which punctuation mark should be placed in the blank to ensure the sentence is grammatically correct and internally consistent?

Fill in the blanks below

Though he never completed a working prototype, Charles Babbage envisioned a device that would lay the foundation for modern computing. The development of this theoretical machine—the Analytical Engine, a general-purpose computer designed to utilize punched cards for programming anticipated the digital age by nearly a century. Babbage’s collaborator, Ada Lovelace, even wrote the first algorithm intended for the engine, cementing their place in technological history.
Show answer & explanation

Answer

A dash (or em dash) is required to close the nonessential parenthetical phrase that begins with a dash.
A dash is required to close the parenthetical element. Because the parenthetical phrase starts with a dash after 'machine,' it must be closed with a matching dash after 'programming' to maintain consistent punctuation structure.

Step-by-Step Solution

1
Identify the nonessential parenthetical phrase within the sentence.
The phrase is 'the Analytical Engine, a general-purpose computer designed to utilize punched cards for programming'.
Determining where the parenthetical information begins and ends is necessary to apply the correct punctuation rules.
2
Examine the punctuation mark used to open the parenthetical phrase.
An em dash ('—') is placed immediately after 'theoretical machine' to introduce the parenthetical phrase.
Punctuation marks that set off nonessential information must be symmetrical and consistent.
3
Determine the correct punctuation mark for the blank to close the phrase.
Since the phrase began with a dash, it must close with a matching dash after 'programming'.
Mismatching punctuation marks (such as using a comma to close a phrase opened with a dash) is grammatically incorrect on the ACT.

Key Concept

Dash consistency in parenthetical elements
Question 906Question

Community gardens have blossomed in urban areas over the last decade, transforming vacant lots into vibrant green spaces. These gardens not only provide fresh produce to neighborhoods that lack access to grocery stores, but they also foster a sense of community among diverse groups of residents. Volunteers work side-by-side, sharing gardening tips and building relationships that transcend age and cultural barriers.

[1] Indeed, many people enjoy working in these gardens every weekend. Over time, the lack of city funding or organizational support can cause these gardens to fall into disrepair. Soil testing, water access, and tools require ongoing investment that neighborhood volunteers often cannot afford on their own. Without a long-term management plan, many promising community gardens are eventually abandoned.

Which choice provides the most effective transition from the preceding paragraph to the paragraph that follows?

Show answer & explanation

Answer: However, keeping these community projects running requires constant effort and resources.

Answer

The choice that states 'However, keeping these community projects running requires constant effort and resources' is the correct answer.
The correct answer effectively transitions from the positive impacts of community gardens described in the first paragraph to the financial and physical challenges described in the second paragraph. By using the transition word 'However' and introducing the ideas of 'effort' and 'resources,' it sets up the discussion of funding, water access, and tools that follows.

Step-by-Step Solution

1
Analyze the relationship between the first and second paragraphs.
The first paragraph discusses the positive aspects and benefits of community gardens, while the second paragraph details the challenges, costs, and high rate of abandonment.
Understanding the logical relationship (contrast) is necessary to choose the correct transition.
2
Evaluate the rhetorical effectiveness of each option in establishing this contrast.
The transition must signal a shift from positive to negative, making the choice starting with 'However, keeping these community projects running' a strong candidate.
An effective transition must bridge the content of both paragraphs seamlessly.
3
Check the remaining options for grammatical correctness.
The option containing a comma splice and the option using the incorrect preposition 'depends with' are eliminated due to grammatical errors.
ACT questions require the correct answer to be both rhetorically effective and grammatically correct.

Key Concept

Paragraph-level transitions establish logical connections between the main ideas of adjacent paragraphs, ensuring a smooth flow of information.
Question 907Question

In 1938, Marjorie Courtenay-Latimer, a South African museum curator, received a call from a local fisherman who had caught a bizarre, heavy fish with limb-like lobed fins and an armored head. Recognizing its uniqueness, she sent descriptions to J.L.B. Smith, a prominent chemist and amateur ichthyologist, who identified it as a coelacanth—a primitive fish believed to have gone extinct 66 million years ago. This shocking discovery shook the scientific community, challenging long-held assumptions about the fossil record and the evolutionary history of vertebrates.

To find more specimens, Smith launched a decades-long search along the coast of the Indian Ocean, eventually discovering a second population near the Comoro Islands. Researchers soon realized that the coelacanth was not merely a lone survivor but part of a resilient, deep-water ecosystem that had remained largely undisturbed for eons. Consequently, J.L.B. Smith spent many years traveling along the coast of Africa looking for more of these creatures.

The writer wants to conclude the passage by emphasizing that the coelacanth's discovery continues to influence modern marine biology. Given that all the choices are true, which choice best accomplishes this goal?

Show answer & explanation

Answer: Indeed, this extraordinary find continues to inspire marine biologists to explore the unresolved mysteries of the deep ocean.

Answer

The option stating that the extraordinary find continues to inspire marine biologists to explore deep-ocean mysteries is correct because it directly satisfies the rhetorical goal of highlighting the ongoing influence of the discovery, while remaining grammatically correct.
The correct option is the sentence stating that the find continues to inspire marine biologists to explore the unresolved mysteries of the deep ocean. This choice directly satisfies the prompt's request to show the discovery's ongoing impact on modern marine biology, and it is grammatically correct.

Step-by-Step Solution

1
Identify the specific rhetorical goal set by the prompt.
The goal is to select a concluding sentence that emphasizes how the coelacanth's discovery continues to influence modern marine biology.
This establishes the primary criterion for evaluating the options based on their content.
2
Eliminate options that contain grammatical errors.
The option with the phrase 'biologists, they hope' is eliminated due to a comma splice. The option with 'will explore... and discovered' is eliminated due to an illogical tense shift.
Grammatical accuracy is a prerequisite for any correct answer on the ACT English section.
3
Evaluate the remaining grammatically correct options against the rhetorical goal.
The option to keep the original text ('NO CHANGE') only details historical events. The option stating that the find 'continues to inspire marine biologists to explore' successfully connects the historic discovery to modern scientific endeavors.
Comparing the focus of the remaining choices ensures the selected sentence fulfills the writer's specific purpose.

Key Concept

Selecting Concluding Sentences
Estimated Time:1m 0s
Question 908Question

The following passage is an essay about the ancient city of Petra.

[1]
Deep within the desert canyons of modern-day Jordan lies the ancient city of Petra, famous for its grand, red-sandstone facades carved directly into the cliff faces. Established as the capital of the Nabataean Kingdom as early as the fourth century BCE, Petra thrived as a major trading hub. However, its survival and prosperity in an arid environment depended not on its trade routes, but on the Nabataeans’ remarkable engineering: a sophisticated water management system.

[2]
The Nabataeans engineered a system that harnessed the region's rare but torrential flash floods. They constructed dams to redirect floodwaters away from the city center, preventing destruction, and routed the water into a network of cisterns and reservoirs carved into the rock. Aqueducts and ceramic pipes, pressurized to control flow rates, carried fresh spring water from miles away directly into the heart of the city. This engineering feat ensured a reliable year-round water supply for a population of over twenty thousand.

[3]
This mastery of water resource engineering transformed Petra from a barren outpost into a lush, oasis-like metropolis, complete with public gardens and fountains. By controlling the water supply, the Nabataeans not only secured their survival but also solidified their political and economic power in the region, demonstrating that human ingenuity could conquer one of nature's harshest landscapes.

Suppose the writer's goal had been to write an essay detailing how the Nabataeans engineered a water management system to sustain their desert capital. Is the statement that the essay successfully achieves this goal true or false?

Show answer & explanation

Answer: True

Answer

True
The statement is true because the passage consistently focuses on the engineering, construction, and impact of Petra's water management system, which directly fulfills the writer's goal.

Step-by-Step Solution

1
Identify the hypothetical goal specified in the prompt: to write an essay detailing how the Nabataeans engineered a water management system to sustain their capital.
Hypothetical goal identified.
Establishing the target goal allows comparison with the actual text.
2
Analyze the passage to determine the primary topic and focus.
The passage discusses Petra's arid environment and describes the specific engineering components (dams, cisterns, aqueducts, and pipes) of the Nabataeans' water system.
Determining the actual content is necessary to evaluate if the goal is met.
3
Compare the actual content to the hypothetical goal.
The actual content directly aligns with the goal of detailing the engineering of the water management system, meaning the essay successfully achieves the goal.
Comparing actual focus to the goal yields the final evaluation of true or false.

Key Concept

Evaluating Whole-Essay Goals and Purpose
Estimated Time:1m 30s
Question 909Question

Deep within a sandstone mountain on the Norwegian island of Spitsbergen lies the Svalbard Global Seed Vault, often referred to as the "Doomsday Vault." Designed to withstand natural and man-made disasters, the facility serves as a safety net for the world's agricultural biodiversity. It stores millions of seed samples from across the globe, preserving them in sub-zero temperatures. In the event of a global catastrophe or localized crop failure, these seeds can be retrieved to restart agricultural production.

While some critics argue that the resources spent on the vault would be better utilized in supporting active farming communities, proponents emphasize its long-term security benefits. Indeed, the vault has already proved its value. In 2015, researchers from the Middle East withdrew seeds to replace a gene bank destroyed by conflict. __________

Which of the following sentences, if added at the placeholder, would provide the most effective conclusion to the passage by reinforcing its main theme?

Show answer & explanation

Answer: This successful retrieval demonstrated that the vault is not merely a precautionary concept, but a crucial safeguard for the future of global food security.

Answer

The sentence stating that the successful retrieval demonstrated that the vault is not merely a precautionary concept, but a crucial safeguard for the future of global food security.
The sentence that describes the retrieval as demonstrating the vault's role as a crucial safeguard is the most effective conclusion. It directly links the specific evidence in the second paragraph (the 2015 seed withdrawal) back to the main thesis established in the first paragraph (that the vault serves as a global agricultural safety net). It is also grammatically correct.

Step-by-Step Solution

1
Analyze the main idea of the passage.
The passage discusses the purpose of the Svalbard Global Seed Vault as a safeguard for global agricultural biodiversity and food security, and provides a real-world example of its success.
An effective conclusion must reinforce the primary theme without introducing unrelated details.
2
Evaluate the grammar and structure of each choice.
One option contains a comma splice, another contains an improper tense shift, one contains a weak conclusion with minor technical details, and one is grammatically sound and rhetorically appropriate.
The correct answer on the ACT must be both grammatically correct and rhetorically effective.
3
Select the sentence that summarizes the main thesis and maintains grammatical integrity.
The statement emphasizing the vault as a crucial safeguard for food security successfully ties the real-world example back to the global security thesis.
This choice resolves the passage's discussion with a strong concluding thought.

Key Concept

Selecting Concluding Sentences and Transitions
Estimated Time:1m 0s
Question 910Question

The sentences below are from a draft of a biographical essay about inventor Mary Anderson. Arrange the sentences in the most logical order to show how Anderson's observations of a transportation hazard led directly to her development of a practical safety device.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence begins with the introduction of Mary Anderson's streetcar ride, followed by the description of the driver's struggle with the open window, then the detail about Anderson's sketch of the rubber blade and lever, and ends with the evaluation of the device's success.
The correct order follows a clear chronological and logical progression: first, the setting and initial observation are established; second, the specific problem is detailed; third, the invention is designed to solve that problem; and fourth, the final success and legacy of the device are stated.

Step-by-Step Solution

1
Identify the introductory sentence that establishes the setting and core subject.
The sentence introducing Mary Anderson in 1903 on a New York City streetcar must be placed first.
It provides the necessary background and introduces the driver's struggle, which is the starting point of the narrative.
2
Find the sentence that elaborates on the specific problem or hazard introduced in the first step.
The sentence beginning with 'Because the vehicle lacked any mechanism...' must be placed second.
It directly explains the cause of the driver's struggle and describes the resulting passenger discomfort and hazard.
3
Determine the sentence that describes the action taken to resolve the described problem.
The sentence starting with 'Determined to find a solution...' must be placed third.
It describes Anderson's design process, which is a direct response to the problem of the open window described in the preceding sentence.
4
Locate the sentence that evaluates the success and long-term impact of the invention.
The sentence starting with 'This manually operated device...' must be placed last.
The demonstrative adjective 'This' refers back to the device described in the third step, and the sentence provides a logical conclusion by noting the device's historical significance.

Key Concept

Logical sequencing of supporting details
Question 911Question

The writer is considering deleting the underlined sentence from the following paragraph:

In 1869, Austria introduced the 'Correspondenz-Karte,' which is widely considered the world's first official postcard. Unlike letters, these cards did not require envelopes, making them a cheaper and faster way to send short messages. They quickly gained popularity across Europe, as millions of people embraced this convenient new form of communication. Many early postcards featured simple decorative borders or small illustrations of famous landmarks. The first postage stamps had been introduced in Great Britain in 1840, featuring the profile of Queen Victoria. By the late nineteenth century, the postcard craze had spread globally, transforming how people shared quick updates with friends and family.

Should the writer make this deletion?

Show answer & explanation

Answer: Yes, because it introduces details about the history of postage stamps that are irrelevant to the paragraph's focus on postcards.

Answer

Yes, because it introduces details about the history of postage stamps that are irrelevant to the paragraph's focus on postcards.
The correct option is correct because the paragraph describes the history, development, and spread of postcards. A detail about the 1840 introduction of British postage stamps is irrelevant to the development of postcards in the late nineteenth century and should be deleted.

Step-by-Step Solution

1
Determine the main topic and focus of the paragraph.
The paragraph is focused on the introduction of the first official postcard in Austria and its subsequent design features and global popularity in the late nineteenth century.
Establishing the main focus is necessary to evaluate whether the underlined sentence supports that focus.
2
Analyze the content of the underlined sentence.
The underlined sentence states that the first postage stamps were introduced in Great Britain in 1840 and featured the profile of Queen Victoria.
Understanding the specific information provided in the sentence helps determine if it fits logically into the paragraph.
3
Evaluate the relevance of the sentence to the main focus.
Although both postcards and stamps relate to the mail system, the historical origin of the postage stamp is a separate topic that distracts from the paragraph's development of postcard history. Therefore, the sentence should be deleted.
Comparing the sentence to the paragraph's focus leads to the final decision to delete the sentence due to irrelevance.

Key Concept

Evaluating the relevance of supporting details to the central topic of a paragraph.
Question 912Question

Passage Excerpt:

In 1981, a committee selected twenty-one-year-old architecture student Maya Lin’s design for the Vietnam Veterans Memorial in Washington, D.C. Rather than proposing a traditional, towering monument of white marble, Lin envisioned a simple, polished black granite wall cut into the earth. The names of the fallen soldiers would be carved chronologically onto the reflective surface, allowing visitors to see their own faces superimposed on the names of the dead. This design choice sparked considerable debate initially, but it eventually came to be recognized as a masterpiece of commemorative art.

Given that all the choices are true, which one best emphasizes the emotional and reflective connection between the visitors and the memorial, while maintaining the passage's somber, respectful tone?

Show answer & explanation

Answer: allowing visitors to see their own faces superimposed on the names of the dead, creating a quiet, deeply personal connection between the living and the lost.

Answer

The correct choice is the option that describes the quiet, deeply personal connection between the living and the lost, as it successfully highlights the emotional and reflective connection between visitors and the memorial while preserving the somber, respectful tone.
The correct choice is the phrase that mentions the quiet, deeply personal connection between the living and the lost because it directly emphasizes the emotional and reflective bond between the visitors and the memorial, while maintaining a somber, respectful tone appropriate for the passage.

Step-by-Step Solution

1
Identify the specific rhetorical goal stated in the prompt.
The prompt requires an option that emphasizes the emotional and reflective connection between the visitors and the memorial, and maintains a somber, respectful tone.
Understanding the exact criteria is necessary to evaluate the options effectively.
2
Evaluate each option against the rhetorical criteria and grammatical correctness.
The option describing the 'quiet, deeply personal connection' fits the tone and goal. The option mentioning 'industrial abrasive compounds' is too technical. The option referencing a 'popular tourist attraction' is too casual. The option with 'visitors could see... this created' is a comma splice.
This narrows down the choices to the one that is both grammatically correct and rhetorically appropriate.
3
Select the option that meets both requirements.
The option starting with 'allowing visitors to see...' and ending with 'between the living and the lost' is selected.
It is grammatically sound and fully achieves the specified rhetorical goal.

Key Concept

Meeting Specific Rhetorical Goals
Question 913Question

In 1938, a South African museum curator named Marjorie Courtenay-Latimer discovered an unusual blue fish among a local trawler's catch. The specimen, which had lobe-like fins and a three-lobed tail, was later identified as a coelacanth. Scientists were astonished because this lineage of fish was believed to have gone extinct over sixty million years ago.

Which choice correctly punctuates the underlined portion of the passage?

Show answer & explanation

Answer: NO CHANGE

Answer

The correct answer is the original phrasing, which correctly uses a pair of commas to enclose the nonessential relative clause.
The relative clause 'which had lobe-like fins and a three-lobed tail' is a nonessential (nonrestrictive) clause because it provides extra description about the specimen but is not required to identify it. Nonessential clauses must be set off from the rest of the sentence by a pair of commas. The original phrasing correctly places a comma before 'which' and a comma after 'tail'.

Step-by-Step Solution

1
Identify whether the underlined relative clause is essential (restrictive) or nonessential (nonrestrictive) to the meaning of the sentence.
The clause 'which had lobe-like fins and a three-lobed tail' provides descriptive detail about the specimen but is not needed to identify which specimen is being referred to. Therefore, the clause is nonessential.
Distinguishing between essential and nonessential information determines whether punctuation (like commas) is required to set off the clause.
2
Determine the correct punctuation rules for setting off a nonessential relative clause.
Nonessential clauses must be set off from the rest of the sentence by a pair of commas: one at the start of the clause and one at the end.
Using a pair of commas correctly signals to the reader that the enclosed information is parenthetical and can be omitted without changing the core meaning of the sentence.
3
Evaluate the options to find the one that correctly applies a pair of commas without creating other errors.
The original sentence correctly places a comma before 'which' and a comma after 'tail', meaning no change is needed.
This verifies that the original punctuation is correct and that the other options introduce punctuation errors like dangling commas, incorrect pronouns, or sentence fragments.

Key Concept

Commas with Nonessential and Parenthetical Elements
Estimated Time:1m 0s
Question 914Question

Maya Hieroglyphs

[1] __________________________________________________ Historically, scholars like Eric Thompson argued that the glyphs were merely logographic symbols representing dates and astronomical concepts, with no phonetic elements. This view dominated Mayanist studies for decades, creating a consensus that Mayan writing could never be read phonetically. However, in the mid-twentieth century, Yuri Knorozov, a Soviet linguist, proposed that the glyphs represented syllables in addition to logograms. By comparing the signs in the surviving codices with spoken Mayan languages, Knorozov demonstrated that the script could indeed transcribe the sounds of spoken language, a breakthrough that revolutionized the field of Mesoamerican archaeology.

Knorozov's phonetic approach met with fierce resistance from the established academic community, but it eventually gained traction as other researchers successfully deciphered names, dynasties, and historical events recorded on monuments. The resulting translations transformed our understanding of Classic Maya society from a peaceful, stargazing civilization into one of complex political alliances, warfare, and rich literature.

The writer wants to begin the passage with a sentence that establishes its main focus: the shift in how scholars understood Mayan hieroglyphs. Which of the following sentences, if added at [1], would best accomplish this goal?

Show answer & explanation

Answer: Mainstream Mayanist studies initially rejected the idea that Maya hieroglyphs represented spoken sounds, but a mid-twentieth-century breakthrough revealed that the script was a complex combination of phonetic syllables and word symbols.

Answer

Mainstream Mayanist studies initially rejected the idea that Maya hieroglyphs represented spoken sounds, but a mid-twentieth-century breakthrough revealed that the script was a complex combination of phonetic syllables and word symbols.
The correct answer is grammatically sound and establishes the main focus of the passage. It highlights both the initial consensus (that the hieroglyphs did not represent spoken sounds) and the mid-twentieth-century phonetic breakthrough, setting up the historical contrast detailed in the paragraphs.

Step-by-Step Solution

1
Analyze the passage to determine its main focus and rhetorical structure.
The passage discusses the shift from the historical view that Mayan hieroglyphs were purely symbolic/non-phonetic to Yuri Knorozov's mid-twentieth-century breakthrough proving they represented spoken syllables.
This defines the target content and focus that the introductory sentence must establish.
2
Evaluate the grammatical correctness of each option.
Identify that the option beginning with 'Because' is a fragment (dependent clause); the option with 'consensus... have maintained' has a subject-verb agreement error; and the option using a semicolon before 'although' is ungrammatical because it separates a dependent clause from an independent clause.
Any option containing a grammatical error must be eliminated, regardless of its content.
3
Select the option that is both grammatically sound and rhetorically effective.
The option starting with 'Mainstream Mayanist studies initially rejected...' is grammatically correct and perfectly introduces the shift in scholarly consensus.
This sentence fulfills both grammatical correctness and the rhetorical goal of introducing the passage's main focus.

Key Concept

Establishing Introductions and Thesis Statements
Question 915Question

The following paragraph describes the invention of the QWERTY keyboard layout:

In 1868, printer and inventor Christopher Latham Sholes patented the first commercially successful typewriter. Sholes’s early models, however, had a frustrating flaw: if a typist struck adjacent keys in rapid succession, the metal typebars would easily collide and jam. To solve this problem, Sholes designed the QWERTY keyboard layout, placing frequently used letter pairs far apart on the keyboard. This design forced typists to work slightly slower, which successfully prevented the mechanical bars from sticking together. __________

Which of the following concluding sentences would best wrap up the paragraph by emphasizing the long-lasting impact of Sholes's invention?

Show answer & explanation

Answer: Today, long after the disappearance of mechanical typebars, the QWERTY layout remains the standard keyboard design for computers and smartphones worldwide.

Answer

The option stating that the QWERTY layout remains the standard keyboard design for computers and smartphones worldwide is the correct answer.
The correct choice effectively summarizes the development of the layout and highlights its lasting modern impact, all while remaining grammatically correct.

Step-by-Step Solution

1
Analyze the prompt's request.
The correct sentence must summarize the passage and specifically highlight the long-lasting impact of Sholes's layout.
This establishes the criteria for evaluating the choices.
2
Evaluate the choices for relevance and focus.
The option about Sholes selling his typewriter rights introduces unrelated financial details, failing to wrap up the main theme.
Irrelevant biographical details weaken the paragraph's conclusion.
3
Check the remaining choices for grammatical correctness.
The option mentioning that layout options have changed contains a comma splice, and the option claiming manufacturers still used the layout contains a tense shift. The option noting that QWERTY remains the standard keyboard design is both relevant and grammatically sound.
Concluding sentences must be free of grammatical errors to be effective.

Key Concept

Selecting a concluding sentence that summarizes the main thesis while maintaining correct grammar and avoiding unrelated details.
Question 916Question

Before the final spacecraft launch, the mission controllers double-checked the telemetry data. The controllers' primary worry was it's potential to be corrupted during transmission, which would jeopardize the entire landing sequence.

Which of the following options completes the underlined portion of the sentence in a grammatically correct way?

Show answer & explanation

Answer: controllers' primary worry was its

Answer

controllers' primary worry was its
The correct option properly uses 'controllers'' to show that the worry belongs to the plural group of controllers mentioned in the previous sentence. It also correctly uses 'its' as the possessive pronoun referring to the telemetry data.

Step-by-Step Solution

1
Determine if the noun 'controllers' should be singular or plural, and possessive.
The first sentence mentions 'mission controllers' (plural). Because the worry belongs to these controllers, a plural possessive form is needed, which is written as 'controllers''.
To show possession for a plural noun ending in 's', the apostrophe must go after the 's'.
2
Determine whether to use 'its' or 'it's'.
The sentence refers to the potential of the telemetry data. Therefore, the possessive pronoun 'its' is required.
'It's' is a contraction for 'it is' or 'it has', whereas 'its' is the possessive pronoun form.
3
Combine the correct plural possessive noun and the correct possessive pronoun.
The correct phrase is 'controllers' primary worry was its'.
This combination satisfies both the plural noun possession requirement and the possessive pronoun requirement.

Key Concept

Using plural possessive nouns and distinguishing between possessive pronouns and contractions
Question 917Question

For decades, archaeologists assumed that the builders of Stonehenge were local Neolithic farmers who spent their entire lives within a few miles of the monument. Recent analyses of strontium isotopes in the teeth of individuals buried near the site have challenged this view, revealing that many of these people migrated from as far away as modern-day Wales and even continental Europe. Instead, the construction of the monument likely relied on a massive, collaborative network of distinct regional groups.

Which of the following choices best replaces the underlined portion to establish the most logical transition and correct punctuation?

Show answer & explanation

Answer: Europe; consequently, the

Answer

The correct answer correctly uses a semicolon to separate the two independent clauses and selects the conjunctive adverb 'consequently' to establish the logical cause-and-effect relationship between the migration evidence and the conclusion about collaborative networks.
The correct option properly uses a semicolon to separate the two independent clauses and selects the conjunctive adverb 'consequently' to establish the logical cause-and-effect relationship between the migration evidence and the conclusion about collaborative networks.

Step-by-Step Solution

1
Analyze the logical relationship between the two sentences.
The first sentence presents evidence that Stonehenge builders migrated from far-flung regions, while the second sentence concludes that the monument's construction must have required a collaborative regional network. This is a cause-and-effect relationship.
Understanding the logical connection is necessary to choose the correct transition word.
2
Determine the grammatical relationship and punctuation required between the two clauses.
Both clauses are independent and can stand alone as sentences. They must be separated by a period or a semicolon, or joined with a coordinating conjunction. Joining them with a comma and a conjunctive adverb ('consequently') creates a comma splice.
Correct punctuation is required to avoid structural sentence errors.
3
Evaluate the choices for both logical fit and grammatical correctness, eliminating redundant or incorrectly punctuated options.
The transition 'consequently' fits logically, and the semicolon followed by a comma correctly punctuates the transition. Redundant options and comma splices are eliminated.
This identifies the option that satisfies all logical and grammatical criteria.

Key Concept

Sentence-Level Transitions and Punctuation
Estimated Time:1m 0s
Question 918Question

Read the passage below about thermophilic bacteria. Which punctuation mark should be placed in the blank to grammatically connect the two independent clauses?

Fill in the blanks below

Deep within the geothermal pools of Yellowstone National Park, microscopic organisms called thermophiles thrive in boiling water. These extreme microbes possess specialized proteins that do not denature at high temperatures researchers study these enzymes to develop more efficient PCR tests for medical diagnostics. Consequently, these tiny organisms have revolutionized the field of biotechnology.
Show answer & explanation

Answer

A semicolon (;) is the correct punctuation mark to connect the two independent clauses.
A semicolon is the correct punctuation mark because it is used to link two independent clauses that are closely related in thought, especially when there is no coordinating conjunction and the second clause starts with a lowercase letter.

Step-by-Step Solution

1
Analyze the clause preceding the blank.
The clause 'These extreme microbes possess specialized proteins that do not denature at high temperatures' is an independent clause because it contains a subject and a verb and can stand alone as a complete sentence.
To determine the appropriate punctuation, we must first establish the grammatical structure of the surrounding text.
2
Analyze the clause succeeding the blank.
The clause 'researchers study these enzymes to develop more efficient PCR tests for medical diagnostics' is also an independent clause.
Identifying the nature of both clauses helps us choose the correct punctuation mark to link them.
3
Select the correct punctuation mark to join two independent clauses without a coordinating conjunction.
A semicolon is required. Since the second clause begins with a lowercase letter, a period cannot be used. A comma alone would create a grammatically incorrect comma splice.
A semicolon is standard punctuation for connecting closely related independent clauses without a coordinating conjunction.

Key Concept

Using a semicolon to link two independent clauses that are closely related in thought.
Estimated Time:1m 0s
Question 919Question

During the late nineteenth century, the art of botanical illustration underwent a significant shift. While earlier illustrators focused almost exclusively on the aesthetic beauty of flowers to decorate garden catalogs, later illustrators collaborated closely with taxonomists to document minute anatomical details. [1] These illustrators created highly precise drawings of seed pods, root structures, and leaf veins, which were essential for scientific classification. This partnership between art and science elevated botanical illustration from a hobby to an indispensable academic discipline.

The writer is considering adding the following sentence at Point [1]:

"Many of these artists preferred watercolor over oil paint because it dried faster and allowed for finer lines."

Should the writer make this addition?

Show answer & explanation

Answer: No, because it introduces a detail about artistic mediums that departs from the paragraph's focus on the transition toward scientific collaboration.

Answer

No, because it introduces a detail about artistic mediums that departs from the paragraph's focus on the transition toward scientific collaboration.
The correct option correctly identifies that the sentence should not be added because it introduces irrelevant details about artistic mediums (watercolor versus oil paint) that distract from the paragraph's central focus on the development of botanical illustration as a scientific partner to taxonomy.

Step-by-Step Solution

1
Analyze the main focus of the paragraph.
The paragraph describes a historical shift in botanical illustration, transitioning from purely decorative art to a scientific collaboration with taxonomists that elevated the field to an academic discipline.
Understanding the paragraph's theme is necessary to evaluate if the proposed sentence contributes to or disrupts the flow of ideas.
2
Analyze the proposed sentence to be added.
The proposed sentence discusses the artistic preferences and technical advantages of watercolor over oil paint.
Evaluating the content of the proposed addition helps identify if it aligns with the established theme.
3
Determine relevance and choose the correct decision and explanation.
The sentence should not be added because artistic medium preferences distract from the paragraph's primary focus on scientific collaboration. The correct answer must reflect this reasoning.
Comparing the choices reveals that only the option stating the addition should not be made due to a departure from the focus on scientific collaboration is correct.

Key Concept

Evaluating Relevance for Adding or Deleting Content
Question 920Question

Deep within the arid regions of western India, ancient subterranean structures known as stepwells (or *baolis*) served as crucial architectural marvels. First constructed over a thousand years ago to harvest monsoon rains, these engineering feats allowed communities to access water year-round despite the region's hyper-seasonal climate.

[1] Elaborate stone corridors descended multiple stories underground, leading down to cool, shaded pavilions where locals gathered to escape the scorching heat of the afternoon sun. Travelers rested along trade routes, women socialized while retrieving water, and families performed religious rituals, effectively turning a vital water source into a vibrant center of civic life.

Which choice most effectively introduces the second paragraph and establishes its main focus?

Show answer & explanation

Answer: Beyond their primary engineering purpose, stepwells functioned as significant social and cultural hubs.

Answer

Beyond their primary engineering purpose, stepwells functioned as significant social and cultural hubs.
The correct option is grammatically sound and establishes a clear topic sentence that introduces the social and cultural activities detailed in the rest of the paragraph (such as escaping the heat, resting, socializing, and performing rituals).

Step-by-Step Solution

1
Analyze the focus of the second paragraph.
The paragraph describes various social and community activities: gathering to escape the heat, resting during travel, socializing, and performing religious rituals.
To choose the correct introduction, we must first identify the main topic that the paragraph develops.
2
Evaluate the grammar of the options.
One option is a fragment starting with 'Because', one option is a comma splice, and one option shifts to the future and present tenses incorrectly. Only one option is both grammatically correct and stylistically appropriate.
An effective introductory sentence must be grammatically correct.
3
Determine which option best transitionally and conceptually introduces the paragraph's details.
The option referring to stepwells functioning as social and cultural hubs directly sets up the description of community life that follows.
The introductory sentence must prepare the reader for the specific supporting details in the paragraph.

Key Concept

Establishing Introductions and Thesis Statements
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