If you are standing on the ground, it is a safe bet that you are also standing on water (more like, "over" water). Water exists in significant amounts below just about Earth's entire surface. Since you hardly ever see groundwater, it may not be a topic of conversation between you and your friends very often. But it can be! Just take this true/false quiz about groundwater and you will find that you can amaze your friends with little-known facts at the next party.
Finished? You can