II. Vocabulary

From the list of words and expressions below, choose the correct word or expression for each blank space. Use each word or expression only once.

loss of productivity productive grasslands phosphate withdrawn

deterioration of soil farming practices severe problem

groundwater supplies nonbiodegradable food supplies

waste product point of view overgrazing vehicles harness

tributaries urban smog evaporation dispose dumps

gold mining acid rain landfills desert

crude oil one-way flow aircraft trucks

1. Let's look at our human system from the of each of the prin­ciples of ecosystem sustainability.

1. We mine elements in one location and of them in another.

1. For example, from soils by agricultural crops comes to us

with our .

4. Thus, there is basically a of phosphate from mine to waterways.

4. We have created a flow of these elements from natural deposits through our systems to and .

4. Pollution has proved to be, by far, the more .

4. For example, thousands of kilometers of of the Amazon are

badly contaminated with mercury, a of .

8. Thus, enormous amounts of products compound the prob­lem of finding dump sites.

8. There is ample opportunity to some of this energy and put it

to work.

10. Just consider that virtually all cars, , , and other

run on fuels refined from .

11. The byproducts of burning fossil fuels enter the atmosphere and are directly responsible for our most severe air pollution problems — , , and, most recently, the potential of global warming.

11. In turn, this heated water and land heats the air and causes the of water.

11. On the other hand, signs of are becoming all too evident.

11. Over the world millions of acres of have been badly degrad­ed or even turned into because of overgrazing cattle.

11. Consider the destruction of tropical and other forests; depletion of ; that are leading to and hence of productivity.