Answer: They have larger ranges and thresholds.
Explanation: The rank-size rule defines range as the longest distance that a customer will travel to purchase a good or service. Threshold is the minimum market needed to support the supply of a product or service. It is assumed that customers which travel longer distances to purchase a higher-order good or service, and a provider of such goods and services will require a larger customer base to make a profit. Thus, higher-order services have larger ranges and thresholds.
Central Plateau Of Mexico
Answer: Carbon Dioxide
Explanation: Soil aeration is the process that provides the air to the plants and maintains the flow of oxygen and carbon dioxide gases. These are the two most vital gases for the life process of the soil to provide it to the plants and other micro organisms. It provides these gases so that there can be production in the plant through soil.