What is a common example of groundwater?

Groundwater refers to the water that is stored beneath the Earth's surface, primarily in aquifers. It plays a vital role in the water cycle and serves as a significant source of freshwater for drinking, irrigation, and other uses. Wells are a direct and common example of groundwater because they are specifically constructed to access this subsurface water. When a well is drilled into the ground, it reaches into the aquifer where groundwater is stored, allowing for the extraction of water for various purposes.

In contrast, streams, rivers, and reservoirs primarily involve surface water rather than groundwater. Streams and rivers flow over the land and are formed from precipitation runoff or melting snow, while reservoirs are artificial or natural lakes used to store surface water for irrigation, drinking, and recreation. Thus, the correct answer highlights the relationship of wells directly accessing groundwater, whereas the other options pertain to surface water sources.