For many years, the Great Plains was covered by prairie grass. The grass had tough roots that kept the dirt from blowing away. In the 1920s, many farmers moved to the area and plowed up the grass. In the early 1930s, there was very little rain for several years, and the dirt
turned to dry dust. Strong winds blew dark clouds of dust into the sky, and crops were ruined. Because of the dust storms, the area became
known as the Dust Bowl. To escape the "black blizzards," thousands of farm families were forced to leave their homes.
According to the passage, what was one cause of the dust storms?
O 1. Farmers plowed up the prairie grass.
2. Dark clouds of dust formed in the sky.
0 3. Farmers were left with damaged crops.
O 4. Prairie grass broke the dirt up into dust.