Questions 1–5. Select the best word for each blank from the options given.

Questions 6–10. Select the TWO answer choices that both fit the sentence's meaning and produce sentences alike in meaning.

Questions 11–15 are based on the passage below.

Coral reefs occupy less than one percent of the ocean floor yet support roughly a quarter of all known marine species, a disproportion that has long puzzled ecologists. Part of the explanation lies in the reef's physical structure: the branching, cratered architecture built by coral polyps creates an enormous variety of microhabitats within a small area, from sunlit shallows to shaded crevices. But structure alone cannot account for the productivity of reef ecosystems, since the surrounding open ocean is often nutrient-poor. The missing piece is a symbiotic relationship between coral polyps and microscopic algae called zooxanthellae, which live within the coral's tissue and supply it with the products of photosynthesis in exchange for shelter and carbon dioxide. This partnership allows reefs to thrive in waters that would otherwise support little life, a phenomenon researchers sometimes call "Darwin's paradox" after the naturalist first noted the puzzle in the nineteenth century. When ocean temperatures rise even slightly above normal, however, the coral expels its algae in a stress response known as bleaching; a bleached coral is not dead, but it is starving, and prolonged bleaching events can collapse the symbiosis entirely.

Questions 16–20 are based on the passage below.

Economists have traditionally modeled human decision-making as the work of a coolly rational actor who weighs costs and benefits before choosing the option of greatest expected value. Behavioral economics, a field that emerged from a collaboration between psychologists and economists in the 1970s, challenged this assumption by documenting systematic ways in which real decisions deviate from the rational model. One influential finding, loss aversion, showed that people feel the pain of a loss roughly twice as intensely as the pleasure of an equivalent gain — a asymmetry with no place in classical models, which treat a dollar lost and a dollar gained as mirror images. Critics of behavioral economics have argued that such findings, however robust in laboratory settings, may not survive in real markets, where competition and experience are thought to discipline irrational behavior out of participants over time. Proponents counter that loss aversion and related biases persist even among experienced professional traders, suggesting that the effect is not merely a symptom of novice inexperience but a durable feature of human cognition. The debate remains unresolved, but its practical consequences are not: understanding loss aversion has reshaped fields from insurance design to public policy, wherever people must be persuaded to make decisions under uncertainty.