We learned about the water cycle and how all the water in the world keeps going around and around the cycle.  I am amazed that all the water God made on the earth a long time ago is still here.  We made terariums (tera- means earth) that are like little water cycles -- closed systems.  The water in our terariums turns to water vapour and then condenses on the inside of the bottle and then it comes down in drops like rain in the terarium and goes back into the dirt and then the cycle starts all over again.