A. the location of the underground water B. process that converts ammonia into nitrite ions C. water that falls to Earth's surface D. the mass of air surrounding the Earth E. very important to all ecosystems, and ultimately give life on Earth F. plants release water through the pores in their leaves G. plants provide carbon dioxide for the animals H. movement of water through the environment I. animals take in O2 from the atmosphere and give off CO2 J. bacteria that are found in the soil that form root nodules K. series of events that are regularly repeated L. plants food making process M. a living element that humans and animals require to live N. use the Sun's energy and carbon dioxide to make glucose O. enzyme that fixes atmospheric nitrogen (N2) P. one of the products of animal's respiration​