Central Ideas & DetailsHow the SAT tests it — and how to beat it

The following text is adapted from an informational passage written for a broad audience. Marine biologist Keiko Tanaka spent over a decade studying coral reefs in the Pacific Ocean. She noticed that reefs near coastal cities showed more signs of bleaching than reefs farther from human settlements. Tanaka concluded that pollution from urban runoff was a major contributor to coral stress. She recommended that cities near reef systems invest in better water filtration to reduce the amount of harmful chemicals entering the ocean. According to the text, what did Tanaka conclude was a major cause of coral stress?

The following text is adapted from an informational passage written for a broad audience. In the early twentieth century, the Argentine writer Jorge Luis Borges became fascinated with the concept of infinite libraries. His short story "The Library of Babel" imagines a universe composed entirely of hexagonal rooms filled with books containing every possible combination of characters. While the story is often read as a meditation on the nature of meaning and language, literary scholar María Elena Walsh has argued that Borges was primarily concerned with the psychological toll of limitless information. Walsh points to Borges's personal letters, in which he frequently expressed anxiety about the growing volume of published works and his inability to read them all within a single lifetime. Which choice best states the main idea of the text?