Glossary Asphalt A hard, black petroleum-based material used to pave roads. Asphalt can be mixed with recycled tires to make roads last longer. Aquifer Underground layer of rock or sand that stores water.
Humans use wells to get drinking water from aquifers.
A large amount of something that is not divided into separate packages. Many stores allow shoppers to scoop out the amount they need of bulk goods like popcorn or potato chips. This reduces waste and packaging. Compost A rich, soil-like substance that can be added to a garden to help plants grow. Grass, leaves, paper, and some types of food can naturally decay and turn into compost.