Which statement best describes the Hydrologic Cycle?

• A. A cycle driven primarily by oxygen in the atmosphere.
• B. A process that ignores evaporation.
• C. A closed system of water that continuously moves from the ground to the atmosphere and back.
• D. A one-way flow of water from rivers to oceans.

Answer: (C)

The hydrologic cycle is a closed loop of water moving through the atmosphere, land, and oceans. Solar energy drives evaporation from bodies of water and transpiration from plants, lifting water into the air where it condenses into clouds. Precipitation returns water to the surface, feeding rivers, lakes, soils, and groundwater, and gravity helps pull it back toward Earth's surface and oceans. This continuous movement keeps water in a cycle rather than letting it disappear from the system, making it a closed system of water that flows between ground and atmosphere and back again.

This isn't about oxygen driving the process, and evaporation is a central part of the cycle, not something to be ignored. It's not simply a one-way flow from rivers to oceans; water constantly returns to land and air through precipitation and other pathways, completing the loop.