from Tallgrass Prairie National Preserve, Kansas
1 Tallgrass Prairie National Preserve [in the Flint Hills region of Kansas), established November 12, 1996, is the only unit of the National Park System dedicated to the rich natural and cultural history of the tallgrass prairie ecosystem...
2 Tallgrass prairie once covered more than 170 million acres of the United States, from Indiana to Kansas and from Canada to Texas. Nearly all of it is gone, plowed under for agriculture or urban development. An ancient past survives in the irreplaceable Flint Hills tallgrass. It takes all season for the grasses to reach their maximum heights. The phrase "Tall in the Fall" is one to remember when visiting the preserve. Like everything in nature, they start out small. By early October the grasses reach their limits and turn golden brown.
3 This sea of grass was once a shallow sea of water. Between 200 and 300 million years ago, the gray and white limestone and steel tough flint began to form on the Permian Sea floor. The resulting Flint Hills geology was too shallow and rocky for plowing but excellent for pasture. The natural prairie cycle of weather, fires and animal grazing has sustained the diverse tallgrass ecosystem ever since.
How are the ideas about the tallgrass prairie in paragraphs 2 and 3 related?
1. Paragraph 2 describes a visit to the prairie, and paragraph 3 explains why visiting the prairie is important.
2. Paragraph 2 describes what the prairie is like today, and paragraph 3 explains the way the prairie formed.
3. Paragraph 2 states that the prairie is irreplaceable, and paragraph 3 explains why it should be preserved.
4. Paragraph 2 states that nearly all of the prairie is gone, and paragraph 3 explains what caused it to disappear.