Free SAT Practice Question

Reef-building corals add a new layer of skeleton each year, and within the range of temperatures a coral can tolerate, the width of that yearly band depends on the water: warmer water speeds the coral’s growth and yields a wider band, while cooler water slows it and yields a narrower one. Examining a coral colony that had grown in a shallow lagoon, a team found that the bands laid down during one stretch of the eighteenth century were consistently narrower than the bands formed just before and just after that stretch. Because the lagoon was shallow enough that its water temperature closely followed the temperature of the surrounding region, the researchers concluded that, during that stretch, the region’s climate was most likely ______