Answer:
1) large population centers; (2) monumental architecture and unique art styles; (3) shared communication strategies; (4) systems for administering territories; (5) a complex division of labor; and (6) the division of people into social and economic classes.
Source: Key Components of Civilization - National Geographic Society 
 
        
             
        
        
        
Poor farming practices.
<h3>Further explanation</h3>
- The Dust Bowl natural disaster occurred in the Midwest in the 1930s in North America. The effect lasts for a long period in 27 states and drought afflicts 75% of the country.
- Dust and drought shake great an enormous portion of U.S. agricultural production. Undoubtedly this natural disaster even worsened the Great Depression that was happening in the US at that time.
- In addition to factors due to shifting weather patterns that occur over the Atlantic and Pacific oceans, this natural disaster is also caused by poor farming practices because it is unsustainable and poorly planned. That negligence also weakens plants that prevent the soil in place.    
- Formerly in the Midwest, prairies grass protected the topsoil and was so profitable. But once the farmers finished processing it, they plowed more than 5.2 million hectares of deep-rooted grass.
- Land wealth just disappeared after years of farming. A strong wind blew the rest of the topsoil, and the drought prevented the plants. 
- When the wind blew, they dissipate a massive cloud of dust. It piled up mounds of land everywhere that covered much of the housing.
- The Dust Bowl affected the entire Midwest. Dust suffocated livestock and caused pneumonia in children.
- By 1941, the Dust Bowl gradually receded along with the level of rainfall that had returned to near-normal levels. The Great Depression also ended.
<h3>Learn more</h3>
- The reason why President Johnson decided not to run for reelection in 1968 brainly.com/question/2155898
- In the Great Compromise, the ideas of the Virginia Plan are represented in the House of Representatives brainly.com/question/10941511
- Continental crust is generally older than oceanic crust brainly.com/question/10537829
Keywords: The 1930s, Dust Bowl in the Great Plains was caused by, deforestation, contour plowing, using renewable resources, poor farming practices, the natural disaster, Midwest, US, the Atlantic, and Pacific Oceans
 
        
                    
             
        
        
        
Answer:
During the second half of the 1920s, Joseph Stalin set the stage for gaining absolute power by employing police repression against opposition elements within the Communist Party. The machinery of coercion had previously been used only against opponents of Bolshevism, not against party members themselves. The first victims were Politburo members Leon Trotskii, Grigorii Zinov'ev, and Lev Kamenev, who were defeated and expelled from the party in late 1927. Stalin then turned against Nikolai Bukharin, who was denounced as a “right opposition,” for opposing his policy of forced collectivization and rapid industrialization at the expense of the peasantry.
Explanation:
 
        
             
        
        
        
Answer:
Explanation:
they were helping each other so they could get there land back