Question

where might a spring form?
○ between the saturated and unsaturated zones
○ at the bottom of a deep valley
○ on a mountaintop at the origin of a stream
○ on the surface of a fast-moving aquifer

Explanation:

To determine where a spring forms, we analyze each option:

• A spring forms where the water table (boundary between saturated and unsaturated zones) intersects the land surface, allowing groundwater to emerge.
• "At the bottom of a deep valley" is not specific to spring formation (valleys can have springs but this is not the defining location).
• "On a mountaintop at the origin of a stream" describes stream headwaters, not spring formation (springs involve groundwater, not just stream sources).
• "On the surface of a fast - moving aquifer" is incorrect as aquifers are underground, and springs relate to the water table - surface intersection.

Answer:

between the saturated and unsaturated zones