5
gases that contribute to the greenhouse effect
6
a measurement of the impact human activities have on future generations' ability to live on & use the Earth's resources
7
excessive richness of nutrients in a body of water, frequently due to runoff of agricultural chemicals from the land
17
produced without chemical agents, like pesticides, fertilizers, etc.
20
Normally, _____ items take up to 1000 years to degrade in a landfill.
