III. Prepositions
Pill in the correct preposition for each blank space.
1 ■ Let's look our human system the point view
each the principles ecosystem sustainability.
6'
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Ecosystems: How They Work
77
2. For
sustainability ecosystems dispose wastes
and replenish
nutrients recycling all elements.
3. We mine elements one location and dispose them
another.
4. For example, phosphate withdrawn soils agricultur al crops comes us our food supplies, but then efflu ents our wastes containing the phosphate are discharged
various waterways rather than back the soil.
Likewise, many rivers and other bodies water are contaminated toxic elements various discharges.
For example, thousands kilometers tributaries
the Amazon are badly contaminated mercury, a waste prod uct gold mining.
7. Seventy percent the electricity our country comes
coal-fired power plants, and most homes, buildings, and
hot water are heated natural gas.
8. all, more than 10 calories fossil fuels are consumed
every calorie food that is served the U.S.
9. Most the rest is converted directly heat as it is ab sorbed water or land.
10. Therefore, even using solar energy a vast scale would not
change the overall dynamics the biosphere.
11. It has nearly tripled just the last 60 years and is continuing
to increase a rate over 90 mln people per year.
12. Then, there are any number examples overgrazing
figurative sense.
IV. DEFINITE/INDEFINITE ARTICLES
Use a/an or the where needed. If no article is needed, write an AT in the blank space.
Thus, danger in continuing to ignore ecosys tem principle regarding solar energy seems clear. In ad dition to being nonpolluting and nondepletable, solar energy is
also extremely abundant. Green plants, including crops utilize
very small fraction of solar energy that hits earth.
Most of rest is converted directly to heat as it is absorbed
by water or land. In turn, this heated water and
land heats air and causes evaporation of
water. Thus, solar energy is major driving force behind
ocean currents, wind, and rain, - i.e.
weather. There is ample opportunity to harness some of this
energy and put it to work. According to Laws of Ther modynamics, final heat at end of line is
same whether energy is harnessed to perform useful work
along _____ way or not. Therefore, even using solar energy on
vast scale would not change overall dynamics of
biosphere.
V. VALUES DISCUSSION Answer the following questions, then discuss your answers with your classmates.
1. What may basic ecological principles of sustainability show us?
a. The environmental problems we face.
b. Our failure to adhere to these principles, с The direction we need to take.
d. other
2. What do we do in contrast to First Principle of Sustainability?
a. We mine elements in one location.
b. We dispose of elements in another location.
с We have based our human system on one-directional flow of
elements, d. other
3. Where are effluents of our wastes containing the phosphate dis charging?
a. back into soil с into bays and estuaries
b. into various waterways d. other
4. What is done to make up for the removal of phosphate from soil?
a. Phosphate is discharged into various waterways.
b. Phosphate rock is mined at various locations.
с Phosphate rock is added to soil as a constituent of fertilizer, d. other
5. What problems does the one-way flow from mine to waterways lead to?
a. ecological disturbances
b. depletion of the resources at one end
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Unit Six
c. pollution at the other end
d. other
6. What has proved to be the more severe problem?
a. phosphate withdrawn с depletion of resources
b. pollution d. other
7. What problem is known as eutrophication?
a. severe ecological disturbances
b. oversupplying with nutrients such as phosphate с contaminating with toxic elements
d. other
8. What fact aggravates the problem of pollution?
a. We produce thousands of products, such as plastics.
b. We use synthetic organic compounds.
с We produce and use nonbiodegradable compounds, d. other
9. What is an encouraging sign that we are beginning to recognize and implement the first principle of sustainability?
a. the rapid development of recycling problems
b. solving the problems of finding dump sites с finding space for dumps and landfills
d. other
10. What do ecosystems use as their source of energy, according to the second principle of sustainability?
a. fossil fuels b. crude oil с sunlight d. other
11. What have we developed in contrast to this principle?
a. vehicles с machinery and engines
b. heating plants d. other
12. Where does 70 percent of electricity in the USA come from?
a. crude oil с coal-fired power plants
b. natural gas d. other
13. What are most homes, buildings, and hot water heated with?
a. electricity b. natural gas с fossil fuels d. other
14. What are the byproducts of burning fossil fuels responsible for?
a. urban smog and acid rain
b. the potential of global warming
с most severe air pollution problems ;y
^ d. other . .4w, '
Ecosystems: How They Work 79
15. What is the major driving force behind weather?
a. natural gas b. crude oil с solar energy d. other
16. What is the third principle of sustainability connected with?
a. the human population с ever-accelerating growth rate
b. overgrazing d. other
17. What examples of literal overgrazing may be given?
a. depletion of fishing area
b. degradation of productive grasslands с picking hillsides bare
d. other
18. What examples of overgrazing in figurative sense are there in the article?
a. deterioration of soils
b. destruction of tropical and Other forests с depletion of groundwater supplies
d. other
19. What is the most serious form of figurative overgrazing?
a. ever-expanding human development and exploitation
b. displacing and degrading of natural ecosystems с the extinction of countless species
d. other