1. environment a scientific hypothesis that has been supported by data and facts over and over again 2. environmental science the external conditions, including natural surroundings, people, attitudes, and anything that influences the life and activities of people, plants, and animals 3. hypothesis a branch of study or knowledge about the physical and material world which is conducted through investigation and observation 4. natural resources materials taken from the natural environment, such as water, air, and plant life 5. sustainability the study of ways in which people and animals interact with their environment 6. science educated guess based on observation and experimentation 7. theory long-term maintenance of ecosystem components that allows them to continue through future generations