This town does not actually exist, but it might easily have a thousand counterparts in America or elsewhere in the world. I know of no community that has experienced all the misfortunes I describe. Yet every one of these disasters has actually happened somewhere, and many real communities have already suffered a substantial number of them. A grim specter has crept upon us almost unnoticed, and this imagined tragedy may easily become a stark reality we all shall know. —Silent Spring, Rachel Carson What is the best description of the author’s purpose in this passage? to convince readers of a threat to explain a frightening story to convince readers of the importance of community to explain a historical event