Read the following passage carefully:
"Geothermal heat pumps utilize the earth's stable subterranean temperature to provide energy-efficient heating and cooling for residential buildings. While surface air temperatures fluctuate drastically across seasons, the ground several feet below the surface remains at a consistent 50 to 60 degrees Fahrenheit year-round. A closed underground loop filled with fluid transfers heat from the earth into the home during winter and reverses the process in summer. Although installing the subsurface pipe network requires substantial initial excavation and specialized drilling equipment, the system drastically lowers long-term electricity consumption."
Match each excerpt from the passage to its correct structural function within the text.
- "Geothermal heat pumps utilize the earth's stable subterranean temperature to provide energy-efficient heating and cooling for residential buildings."Central Main Idea: Encapsulates the overall topic, primary mechanism, and broad functional objective of the entire passage.
- "While surface air temperatures fluctuate drastically across seasons, the ground several feet below the surface remains at a consistent 50 to 60 degrees Fahrenheit year-round."Supporting Scientific Detail: Provides specific physical baseline data and contextual comparison explaining why the mechanism operates.
- "Although installing the subsurface pipe network requires substantial initial excavation and specialized drilling equipment..."Supporting Practical Qualification: Acknowledges a specific installation hurdle without altering the core claim regarding efficiency.