Text Completion - 1

Unlike most deep-sea organisms, which rely on nutrients drifting down from surface waters, the communities clustered around hydrothermal vents on the ocean floor derive their energy from a fundamentally different source: chemosynthesis. Bacteria living near these vents convert hydrogen sulfide — a toxic gas released by volcanic activity — into organic matter, forming the base of a thriving ecosystem. Scientists note that because these communities exist in permanent darkness, far beyond the reach of sunlight, they ______

Which choice most logically completes the text?

• are among the most fragile ecosystems on the planet, with limited capacity to recover from disruption.
• demonstrate that complex life can be sustained without any dependence on solar energy.
• produce larger quantities of organic matter than ecosystems found in shallow coastal waters.
• were the first ecosystems to emerge on Earth during its earliest geological period.

Answer explanation

The passage states these communities exist in 'permanent darkness, far beyond the reach of sunlight' and derive energy from chemosynthesis rather than sunlight. This directly supports the conclusion that complex life can thrive without solar energy. The other options introduce claims about fragility, productivity comparisons, or evolutionary history that the passage does not support.

In the 1950s, psychologist Solomon Asch conducted a series of experiments in which participants were asked to match line lengths — a task with objectively correct answers. When surrounded by actors who deliberately gave wrong answers, many participants conformed to the group's incorrect response despite the evidence before their own eyes. Asch concluded that the desire to fit in with a group can override individual judgment, and that social pressure ______

Which choice most logically completes the text?

• is most powerful in situations where the correct answer is ambiguous or unclear.
• has a less significant effect on behavior than previously assumed by social psychologists.
• is capable of leading people to publicly endorse positions they know to be factually wrong.
• tends to strengthen over time as individuals become more accustomed to group dynamics.

Answer explanation

The passage describes participants giving wrong answers 'despite the evidence before their own eyes' — meaning they knew the correct answer but conformed anyway. Option C directly captures this: social pressure can lead people to endorse positions they know to be wrong. Options A, B, and D all introduce claims not supported by the passage.

The fictional island of Utopia, described by Sir Thomas More in his 1516 work of the same name, features a society in which private property has been abolished and all citizens share equally in the island's resources. More presents the island as a place of harmony and abundance, where no one goes without basic necessities. Scholars debate, however, whether More intended his work as a genuine blueprint for social reform or as a satirical exercise, and consequently ______

Which choice most logically completes the text?

• the influence of Utopia on later political thought has been limited to democratic societies.
• the precise nature of More's intentions in writing the work remains a matter of interpretation.
• More's views on private property have been widely endorsed by mainstream economists.
• Utopia was poorly received by readers at the time of its original publication.

Answer explanation

The passage says scholars debate whether More's intentions were genuine or satirical. 'Consequently' signals the blank must follow from that debate. Option B — that More's intentions remain a matter of interpretation — directly restates this. Options A, C, and D all introduce claims the passage does not make.

During the Cambrian explosion, approximately 541 million years ago, the fossil record shows a dramatic increase in the variety of animal life. Within a geologically brief period, most of the major animal body plans we recognize today first appeared. Paleontologists have proposed numerous explanations for this sudden burst of diversification, ranging from rising oxygen levels to ecological competition and the development of vision. What is not in dispute, however, is that prior to this event, animal life was comparatively simple, meaning that ______

Which choice most logically completes the text?

• most species that exist today evolved directly from organisms that lived during the Cambrian period.
• the variety of animal forms that existed before the Cambrian explosion was significantly more limited.
• evolutionary change has slowed considerably since the Cambrian period ended.
• rising oxygen levels were the single most important trigger for diversification during this period.

Answer explanation

The passage states that 'prior to this event, animal life was comparatively simple.' The blank follows 'meaning that,' so the answer must restate that implication. Option B is the direct logical match: animal life before the Cambrian was less varied. Options A, C, and D all go beyond or contradict what the passage states.

Historians of science have noted a recurring pattern in the acceptance of groundbreaking theories: new ideas that challenge established frameworks are frequently dismissed or ridiculed by the scientific community before eventually gaining acceptance. Alfred Wegener's theory of continental drift, for instance, was rejected for decades before geological evidence confirmed it. This pattern suggests that scientific consensus, while generally reliable, ______

Which choice most logically completes the text?

• is always shaped more by political considerations than by experimental evidence.
• should be rejected whenever it conflicts with an individual researcher's personal observations.
• can sometimes be slow to incorporate ideas that later prove to be correct.
• becomes increasingly resistant to change as a scientific field matures.

Answer explanation

The passage describes a pattern where correct theories are 'dismissed or ridiculed' before gaining acceptance — meaning consensus can lag behind truth. Option C matches this perfectly: consensus 'can sometimes be slow to incorporate ideas that later prove to be correct.' Options A and B are too extreme, and Option D introduces a claim about field maturity not supported by the passage.