1.In the sand and also in the bottom of the cup at the bed rock and it could get stuck in the gravel that is in the cup but it didn't seem like much was stuck in the gravel..
2.It does because each thing in the cup represents the things under ground and shows what really happens to the water that goes in the ground.
3.It can go all the way to the bottom like bedrock which is actually really cool because the bottom is really really deep down.
4.I think that humans do use ground water for things like drinking because it is freshwater and we can only use freshwater to drink.
5.I think that they drill wells into the ground and get the water that is in the well so that we can drink that water in the ground.
6.No I think it stays in the ground where the water is but it will go to bed rock or get in the ground.
7.It stayed about where it was but It kind of supprised me because its pretty cool that a drop of water can make it all the way to the bottom of the cup