Match each short argument on the left with the evidentiary finding on the right that most effectively strengthens its central conclusion.
- Archaeologists excavating pre-Columbian earthworks in the Llanos de Moxos noted that plots enriched with charcoal-based terra preta supported continuous maize cultivation for centuries without nutrient exhaustion. Researchers concluded that the deliberate addition of charcoal compost was the primary factor preventing tropical soil leaching in these fields.Adjacent, identical cultivation plots from the same settlement that received organic mulching without charcoal experienced severe nutrient leaching and were abandoned within two decades.
- Zoologists observed that European robins in metropolitan areas sing at higher frequencies than their rural counterparts. Because city traffic produces loud, low-frequency sound, the researchers concluded that this vocal frequency adjustment is an active behavioral adaptation to prevent traffic noise from masking territorial signals.In controlled laboratory chambers, urban robins systematically shifted to higher pitch only when low-frequency background noise was played, but maintained baseline pitch when exposed to high-frequency noise of identical acoustic amplitude.
- During seventeenth-century Sweden's copper-standard era, commodity prices surged each time the central treasury issued heavy copper plate currency. Economic historians concluded that the domestic price inflation was directly driven by the expansion of the circulating copper money supply rather than by concurrent wartime shipping blockades.In Swedish inland provinces that were entirely self-sufficient in food and domestic goods and thus shielded from shipping disruptions, local commodity inflation tracked the regional injection of newly issued copper plate money.
Answer
Argument 1 (charcoal soil fertility) matches with the control plot finding showing non-charcoal plots suffered leaching; Argument 2 (urban robin vocal frequency) matches with the sound-chamber experiment demonstrating frequency-specific pitch elevation; Argument 3 (Swedish copper inflation) matches with the inland provincial data showing inflation independent of trade blockades.
Each correct match pairs an argument with an empirical finding that eliminates a major competing explanation: the agricultural match uses a negative control to prove charcoal's unique role; the ornithology match uses frequency-selective testing to confirm adaptive signal design; and the economic match uses an insulated market subset to rule out wartime blockades.
Step-by-Step Solution
Key Concept
Evaluating evidentiary support by establishing control comparisons, demonstrating frequency specificity, and eliminating confounding causal variables.
Estimated Time:2m 0s