Practice nine

1-.
Art historians and psychologists often examine the ways in which different colors influence human perception and preference. Research suggests that certain hues evoke feelings of calmness and satisfaction, while others may feel overwhelming or harsh to the eye. For example, people tend to find paintings featuring blues and greens more appealing than paintings featuring yellows and oranges. In this context, the sentence would most logically be completed by emphasizing that some colors naturally draw in more ______ viewers than others.

2.
In discussions about the growing threat of biodiversity loss, one often-cited factor is the role of invasive species. While the spread of these species can have devastating ecological effects, scientists emphasize that human actions can reduce such risks. For example, people can take simple steps such as washing their footwear after travel to avoid introducing potentially invasive organisms into new environments. The sentence suggests that biodiversity loss caused by invasive species is ultimately ______.

3.
Plastic waste presents a serious environmental challenge, and efforts to recycle it have been met with varying success. The process of mechanically recycling plastics is often considered ______ because of both the negative environmental impact of the method and the fact that the materials frequently lose quality after repeated processing. However, chemist Takunda Chazovachii has contributed to the development of a more sustainable process: chemical recycling that converts superabsorbent polymers from diapers into a valuable reusable adhesive.

4.
In the Indigenous intercropping system known as the Three Sisters, maize, squash, and beans are planted together in a way that creates a carefully balanced relationship. Each plant contributes to the health of the others: maize provides a structure on which bean vines can grow; squash spreads across the ground to limit the growth of weeds; and beans replenish the soil with nitrogen. The sentence indicates that these relationships form an ______ web of cooperation that ensures agricultural success.

5.
Marine biologists studying baleen whales have observed that some individuals develop an accessory spleen, a secondary structure of splenic tissue found outside the main organ. At first glance, this formation might appear to serve no real function. However, given its greater prevalence among whales that engage in deeper dives, researchers have hypothesized that its role is not merely ______. Instead, the accessory spleen may provide an important physiological advantage by supporting diving mechanisms.

6.
Luis von Ahn, while working on a project to digitize printed books, noticed that many words were distorted in ways that confused scanning technology, even though human readers could interpret them with relative ease. Building on this insight, he developed a test called reCAPTCHA to distinguish humans from automated “bots.” The system worked by asking users to type one word known to the computer and another word too distorted for scanners to recognize. In doing so, users not only confirmed they were human but also contributed to the process of digitizing books.

7.
The following lines are from Gwendolyn Bennett’s 1926 poem “Street Lamps in Early Spring.” The poem uses rich imagery to depict “Night” through metaphors of clothing and adornment:

Night wears a garment
All velvet soft, all violet blue…
And over her face she draws a veil
As shimmering fine as floating dew…
And here and there
In the black of her hair
The subtle hands of Night
Move slowly with their gem-starred light.

Taken together, the stanzas transform “Night” into a figure with human-like qualities—dressed in velvet, veiled, and adorned with jewels.

8.
The excerpt below is from Jane Austen’s 1814 novel Mansfield Park. In it, the speaker Tom defends the idea of staging a play privately at home with family and friends:

We mean nothing but a little amusement among ourselves, just to vary the scene, and exercise our powers in something new. We want no audience, no publicity. We may be trusted, I think, in choosing some play most perfectly unexceptionable; and I can conceive no greater harm or danger to any of us in conversing in the elegant written language of some respectable author than in chattering in words of our own.

Here, Tom emphasizes both the harmlessness of the play and its limited scope. He reassures others that the group’s performance will be private, respectable, and free from impropriety.

9.
Two texts present competing perspectives on phytoplankton diversity in ocean waters:

Text 1: Ecologists note that thousands of phytoplankton species coexist near the ocean surface, even though conventional wisdom suggests that competition for the same limited resources should allow only one dominant species to survive. Despite extensive research, no single explanation has satisfactorily solved this puzzle.

Text 2: Ecologist Michael Behrenfeld and colleagues propose that phytoplankton diversity is closely linked to their microscopic size. Because the organisms are so small, they are relatively far apart in the water, and the water itself feels “dense” to them. This makes movement and interactions between species limited, thereby reducing direct competition.

10.
The excerpt below is from Sylvia Acevedo’s 2018 memoir Path to the Stars: My Journey from Girl Scout to Rocket Scientist. The narrator recalls traveling by car with her family to Mexico City:

Mario and I played games to see how many different license plates we could spot, and Laura liked to look for children in the back seats of the cars we passed. We were used to the forty-five-minute drive to El Paso and familiar with the six-hour ride to Chihuahua, but I wondered what the long journey to Mexico City would be like.

11.
During the 18th and 19th centuries, European composers sought new ways to manipulate sound and intensify the emotional power of their music. One technique involved expanding the size of orchestras, particularly by adding more brass instruments such as horns, trombones, and tubas. German composer Richard Wagner is especially known for using this technique in his operas, where surges of volume created dramatic, almost overwhelming moments for listeners.

12.
In Classical Nahuatl poetry, a defining feature is the use of difrasismo—a pairing of two nouns that together function as a single metaphor. For instance, the expression in cuauhtli in ocelotl (literally “the eagle, the jaguar”) is conventionally understood to mean “warrior.” Importantly, the relationship between the literal nouns and the figurative meaning is not always straightforward: the metaphor’s function may be more cultural and ritual than purely semantic. Because of this, difrasismos often require knowledge of Aztec ceremonial traditions to be fully understood.

13.
Eighteenth-century economist Adam Smith is widely associated with the metaphor of the “invisible hand,” a phrase often interpreted as a model for how individuals pursuing their own self-interest inadvertently promote the welfare of society as a whole. Yet, as scholar Gavin Kennedy has noted, Smith used this phrase only once in his economic writings, and in a limited context: a critique of mercantilism. Far from being central to Smith’s thought, the metaphor was largely overlooked until the twentieth century, when economists eager to link their own theories to Smith’s prestige elevated the “invisible hand” into a cornerstone of modern economic discourse.

14.
The table below presents approximate rates of speech (syllables per second) and information conveyed (bits per second) for five languages. Researchers studying spoken language across Europe, Asia, and Oceania found that although languages differ substantially in the speed at which syllables are spoken, the overall rate of information communicated varies much less. They concluded that even when languages sound faster or slower, their communicative efficiency remains roughly the same.

15.
The table below presents estimates of bite force for tyrannosaurids, the family of predatory dinosaurs that includes Tarbosaurus, Albertosaurus, and Tyrannosaurus rex. Scientists believe tyrannosaurids had the strongest bite of any land animals in Earth’s history, but estimates vary widely depending on the methods used. Paleontologists Paul Barrett and Emily Rayfield argue that such differences highlight the degree to which methodology influences results.

16.
Psychologists Dacher Keltner and Jonathan Haidt argue that experiencing awe—a feeling of wonder often inspired by something vast, powerful, or beautiful—can encourage people to feel a stronger sense of connection with others and act more altruistically. To test this idea, Keltner, along with Paul Piff, Pia Dietze, and colleagues, conducted an experiment in which one group of participants gazed for a minute at exceptionally tall trees (an experience believed to be awe-inspiring), while another group looked at an ordinary nearby building. Afterward, an experimenter intentionally spilled a box of pens in front of the participants.

17.
The sweet potato (Ipomoea batatas), a staple food crop, originated in South America but was also cultivated centuries ago in Polynesia—long before sustained contact between the two regions. To explain this puzzle, botanist Pablo Muñoz-Rodríguez and colleagues analyzed the DNA of numerous sweet potato varieties. Their findings revealed that Polynesian varieties diverged from South American ones over 100,000 years ago, long before humans first populated Polynesia (within the last 3,000 years). Based on this evidence, the researchers concluded that the presence of sweet potatoes in Polynesia is best explained by natural rather than human-mediated processes.

18
The morphological novelty of echinoderms—marine invertebrates with radial symmetry, usually starlike, around a central point—impedes straightforward comparison with most other animals, in which bilateral symmetry along a head-to-tail axis is the norm. Sea stars, for example, have long puzzled biologists because they are thought to have evolved a headless, radial form from an ancestral body plan that was bilateral. Laurent Formery and colleagues compared genomic markers in acorn worms (Saccoglossus kowalevskii, close relatives of sea stars) with those in the sea star Patiria miniata. Since acorn worms retain the bilateral form, the researchers expected at least partial correspondence in the genes responsible for anterior (head), posterior (tail), and trunk development. Instead, they found activity of anterior genes across nearly the entire body of P. miniata, while posterior genes were active only around the outer edges. Based on these results, the researchers suggested that

19.
African turquoise killifish are unusual among vertebrates because their embryos can remain viable in dry conditions that would normally prevent egg development. When water is scarce, the embryos stop developing and enter a dormant state that can last up to two years—longer than the lifespan of adult fish. This suspended developmental state is called diapause, and it allows the embryos ___ survive until water becomes available again.

20.
The Association of Southeast Asian Nations (ASEAN) was created in 1967 to promote stability and cooperation in the Asia–Pacific region. Its founding members were Thailand, the Philippines, Singapore, Malaysia, and Indonesia. Over the following decades, the organization expanded its membership to include additional countries, and by the end of the 1990s, its size ___ effectively doubled compared with its original formation.

21.
In 2011, the United Kingdom began imposing a small tax—equivalent to just a few cents—on single-use plastic grocery bags. Initially, the policy proved highly effective, with plastic bag consumption falling by as much as ninety percent. ___ measures can be affected by what is known as the “rebound effect”: once consumers adjust to the change, some of the old behavior gradually returns. Indeed, plastic bag use began to creep back up after the initial decline.

22.
In 1966, Emmett Ashford broke barriers in Major League Baseball by becoming the first African American umpire. Known for his energetic and highly visible style, he often announced strikeouts with sweeping gestures and would run quickly after a ball to judge whether it landed out of bounds ___ reshape the public image of the umpire, which had traditionally been one of quiet solemnity.

23.
Arkansas’ Hot Springs National Park contains forty-seven geothermal springs that have long attracted visitors. Scientists have determined that the springs are replenished through a process called natural groundwater recharge: rainwater infiltrates porous rock layers in the nearby hills, percolates downward, and ultimately collects in an underground basin before emerging at the surface as hot springs____ to support the area’s unique ecosystem.

24.
In a grocery store, she set up a booth offering shoppers samples of jam. Sometimes customers could choose among twenty-four different flavors, while other times only six were available. Although more variety might seem attractive, Iyengar found that shoppers who had fewer choices were actually more likely to purchase jam____ those who faced a wider array of options.

25-Communities around the world have empirically demonstrated that common pool resources—such as forests, fisheries, or grazing lands—can be sustainably managed by the people who actually rely on them, without the intervention of either privatizing corporations or centralized state control. In her influential research, political scientist Elinor Ostrom documented numerous cases of communities creating effective local rules and enforcement systems to prevent overuse.
________ Ostrom’s work challenges a long-standing assumption in economics known as the “tragedy of the commons,” the idea that when individuals have free access to a finite shared resource, they will inevitably exploit it until the resource is exhausted.

26
Tourist defacement has become a growing problem in Utah’s Arches National Park, where visitors carve their names or initials into fragile sandstone arches. Park rangers have experimented with different removal techniques. In some cases, carvings can be smoothed away with power grinders, but for deeper carvings this method is impractical because it risks removing large amounts of original rock and permanently altering the natural formation. For these cases, rangers use an “infilling” approach, mixing ground sandstone with a bonding agent and packing it into the carvings to restore the surface. This method is considered minimally invasive because it preserves the integrity of the surrounding rock.

27
In sixteenth-century Spain, the novel Las sergas de Esplandián gained widespread popularity. One of its most striking features was the description of a distant island inhabited solely by Black warrior women, which the author named California. Not long after, Spanish explorers sailing off the west coast of Mexico came upon a large landmass they believed to be an island. Inspired by the novel, they named the place California. In reality, what they had encountered was not an island at all but the long peninsula now called Baja California (“Lower California”), located directly south of the modern U.S. state of California.