front 1 system | back 1 a group of interacting parts that work together as one |
front 2 hydrosphere | back 2 all of the water on planet Earth including lakes, rivers, and oceans |
front 3 atmosphere | back 3 the mixture of gases that surround Earth including oxygen, nitrogen, and carbon dioxide |
front 4 geosphere | back 4 the solid part of the Earth including rocks and dirt |
front 5 biosphere | back 5 all living things on Earth including plants, animals, and humans |