compare and contrast the test structure of the two excerpts. Why do you think each author chose to present information in this way? Working with his dad and brother on land homestead by his maternal great-grandparents just after the Civil War, Justin grew up hearing how his grandmothers put wet tea towels in windows to try to keep out the black blizzard of the Dust Bowl. Given responsibility for several fields while still in high school, he'd watched his own sills blowing and washing away, weeds running out of control and paltry yields. But it wasn't until he went off to Kansas State University that he understood a prime cause of that damage: generations of plowing. Though few landscapes appear more beautiful, fertile and orderly than the straight, black, fragrant furrows of a newly tilled field, plowing is unnatural and , in many climates and soils, one of the most destructive things a farmer can do. Plowing strips soil bare, exposing it to erosion by rain and wind. It collapses soil structure - closing off the water channels left by deep roots and worms - and harms life in the soil, which though it may appear dead is in fact Earth's most biodiverse ecosystem, containing a third of all organisms. Those thousands of microbial species are critical to human survival. They sustain photosynthesis, which all food and oxygen come from, by ferrying nutrients to plants and protecting them from pathogens. They decompose wastes, turning corpses of plants and animals back into new life, They're also directly vital to human health, the source of 90 percent of antibiotics and 60 percent of anticancer drugs